Chapter contents
7.1 Introduction 115
7.2 The complex pulse parameters 115
7.3 Arterial wall tension 116
7.4 Pulse occlusion 120
7.5 CM pulse qualities defined by arterial wall tension and ease of pulse occlusion 123
7.6 Pulse force 137
7.7 CM pulse qualities defined by pulse force 142
7.8 Pulse contour and flow wave 154
7.9 CM pulses defined by pulse contour 158
7.10 Revision of the 27 CM pulse qualities 170
7.11 Using the pulse parameter system 170
7.1. Introduction
This chapter introduces the more complex CM pulse qualities and the pulse parameters associated with them. The complexity of these CM pulse qualities is related to:
• The increased number of changes in pulse parameters associated with each CM pulse quality
• The complexity of each of the associated pulse parameters.
The complex CM pulse qualities are characterised by changes to two or more of the pulse parameters. For each to be defined as a specific CM pulse quality, it is necessary for changes in all the requisite parameters to be present.
7.2. The complex pulse parameters
In this chapter we examine four complex pulse parameters:
• Arterial wall tension
• Ease of occlusion
• Force
• Flow wave and pulse contour.
Although there may be changes in a number of pulse parameters for a complex CM pulse quality, usually one key parameter is considered to be the defining aspect of that particular CM pulse quality. This key parameter is often used to loosely categorise the CM pulse qualities. It should be noted that different CM texts may utilise different ways of grouping the CM pulses, according to differing pulse parameters.
Changes in these pulse parameters are associated with 15 of the 27 traditional CM pulse qualities. The CM pulse qualities associated with each of the complex pulse parameters are:
• Defined primarily by arterial tension and ease of occlusion: Stringlike (Wiry) pulse, Scallion Stalk pulse, Drumskin pulse, Tight pulse, Scattered pulse
• Defined primarily by flow wave and pulse contour: Slippery pulse, Rough pulse, Surging pulse, Stirred pulse.
As noted above, the pulse parameter of pulse occlusion plays an important role in the differentiation of the traditional CM pulse qualities associated with both arterial tension and pulse force.
The complex pulse parameters are so named because, unlike the simple parameters such as rate or rhythm, there is no single objective measurement to definitively evaluate these parameters. They encompass a number of different physiological characteristics involving the actual structure of the artery and the manner in which it responds to the pressure wave that is produced from cardiac contraction. The quality and quantity of blood volume and blood flow, cardiac function and the variability of smooth muscle tone within the arterial wall are equally important factors that impact on the radial artery pulsation. It is the degree to which these factors are involved that determines the specific CM pulse quality produced.
7.3. Arterial wall tension
The parameter of arterial wall tension is a complex pulse parameter, primarily concerned with the physical structure of the artery wall. The degree of arterial wall tension informs us about the functional state of Qi (particularly Yang) in the body. It is necessary to have some tension in the arterial wall. It is when the degree of arterial tension varies from the norm that this is seen as a diagnostic indicator of pathology. For example, variations in tension can result from the stasis or obstruction of Qi and/or blood, an underlying vacuity of Yin fluids and/or blood, or the vacuity of Qi (especially Yang).
The specific CM pulse qualities associated with this parameter are differentiated by the degree of arterial wall tension, ranging from greatly increased tension to a marked reduction. In this sense, it is not the pulse wave that is being assessed but rather the arterial structure. The tension, or lack of tension, in the artery is assessed distinctly differently from the actual shape of the pulse wave.
Five CM pulse qualities are defined primarily by the parameter of arterial wall tension:
• Stringlike (Wiry) pulse (section 7.5.1)
• Tight pulse (section 7.5.2)
• Scallion Stalk pulse (section 7.5.3)
• Drumskin pulse (section 7.5.4)
• Scattered pulse (section 7.5.5).
7.3.1. Differentiation of the CM pulse qualities primarily defined by changes in arterial wall tension
The five CM pulse qualities primarily defined by the degree of tension in the arterial wall range greatly in their presentation. At one extreme is the Stringlike (Wiry) pulse that resists deformation with finger pressure because of the significant increase in arterial wall tension. At the other extreme, the Scattered pulse is characterised by its distinct reduction in arterial tension, which makes it difficult to manually detect the presence of the arterial wall at all. The Drumskin pulse and Scallion Stalk pulse are also defined by the increased tension in the arterial wall. However, when increasing finger pressure is applied to the artery, the arterial wall has only momentary resistance before succumbing to the pressure, a result of their underlying vacuity. In this sense, they are ‘empty’. Further, a distinguishing feature of the Scallion Stalk pulse is the ability of the arterial wall to remain distinct and pliable even when the pulsation in the artery has been occluded.
In addition to changes in arterial wall tension, accompanying changes in other pulse parameters, such as pulse width, force and depth, further differentiate these five CM pulse qualities. However, it is the increase or decrease in tension in the arterial wall of these five pulses that predominantly differentiates them from the other traditional CM pulse qualities.
To further qualify this: the term ‘arterial wall tension’ has been used to encompass a range of different mechanisms that result in the arterial wall being able to be felt distinctly on palpation. The differing mechanisms influence how the increased arterial wall tension manifests in each pulse quality, depending on the involvement of other pulse parameters. For example, the Stringlike (Wiry) pulse and Tight pulse tend to arise due to increased smooth muscle tension within the artery wall, while the Tight pulse may additionally include sclerotic changes to the arterial wall, causing stiffness and a decreased ability to expand easily. So the underlying condition of the arterial wall may well influence how changes in pulse parameters manifest. For the Scallion Stalk pulse, a combination of increased arterial tension and decreased blood viscosity lead to its distinctive manifestation of pliable arterial wall and easy occlusion. This is replicated in the Drumskin pulse but complicated further by the presence of pathogenic Cold.
Constitutional body types may also influence the manner in which changes in pulse parameters present. For example, in an slim individual with a small build, who has smaller arteries than someone with a taller, larger build, increased arterial wall tension may result in a more typically Stringlike (Wiry) type pulse than it would in someone with a wider artery. However, it is the maintenance of this tension with increasing finger pressure, regardless of the width, that signifies the Stringlike (Wiry) pulse.
7.3.2. Definition of arterial wall tension
The degree of arterial wall tension is denoted by the level of clarity or distinctness felt in the artery wall with the palpating fingers.
Three factors are involved in the parameter of arterial wall tension:
• The distensibility and compliance of the arterial wall to pressure changes, whether this occurs internally from the pulse wave or externally from the pressure exerted by the practitioner’s fingertips
• The tone of the smooth muscle component in the arterial wall structure
• Secondary tensile changes occurring in the arterial wall structure unrelated to vascular smooth muscle.
Arterial tension contributes to the perceived ‘hardness’ of the arterial wall on palpation. When arterial tension is present, the artery can be easily distinguished from the tethering support of the surrounding connective tissue. Equally, a lack of arterial tension makes it difficult to distinguish the artery from the surrounding tissue.
Increased arterial wall tension can occur in both replete or vacuity conditions as a result of different physiological mechanisms. For example, increased arterial wall tension may occur in response to Yin vacuity or loss of Yin fluids, resulting in the relative hyperactivity of Yang and accordingly, increased arterial tension. The Scallion Stalk pulse is a good example of a vacuity-type pulse quality, where tension is not associated with vascular smooth muscle contraction but with tension in other parts of the rigid arterial wall structure (see section 7.3.5.2 Alternative mechanism for increased arterial wall tension). Alternatively, a Cold pathogen may lead to increased arterial wall tension by its contracting nature, obstructing Qi and blood flow. This pathogenic factor is considered to be an excess pattern, reflected in an increase in pulse force and arterial width and an increase in arterial wall tension associated with increased smooth muscle tone. The Tight pulse and the Firm pulse are good examples of excess-type CM pulse qualities with increased arterial tension due to contraction of vascular smooth muscle. Qi stasis may also result in hyperactivity of Yang Qi thus leading to increased tension
7.3.3. Arterial wall tension and its assessment
Assessing the arterial wall tension requires the use of two separate techniques:
• Assessment of the physical characteristics of the radial artery wall to determine the degree of arterial tension
• Assessment of pulse occlusion.
7.3.3.1. Assessment of arterial tension
Assessment of arterial wall tension employs the same technique as used in assessment of arterial width. This is initiated by placing the fingers on the skin surface above the radial artery at the three traditional pulse positions and moving them laterally from side to side, using a rolling type motion. This technique has been previously described in section 6.12.1 (see Fig. 6.10 depicting lateral sideways movement of fingers). When the artery is located deeper in the flesh then further finger pressure is required to locate this before moving from side to side. Be careful not to use excessive pressure when assessing for arterial wall tension, because the parameter is associated with both vacuity and replete-type pulses. If too much pressure is applied, then for the vacuity patterns the arterial wall becomes deformed and assessment of the arterial tension is compromised. Pressure needs to move over the artery without compressing it.
7.3.3.2. Assessment of pulse occlusion
Assessment of pulse occlusion requires compression of the arterial wall; in particular, this involves determining what happens to both the arterial wall and the pulsation when increasing pressure is exerted on it by the fingers. That is, does the wall retain its distinctive shape or is it easily deformed, does it easily regain its original form when pressure is released and how easy is it to occlude the arterial pulsation? (Box 7.1)
Box 7.1
Hints for assessing arterial tension
When assessing arterial tension, don’t focus on any pulsatile movement. Rather, your attention needs to focus on the actual arterial structure. The lateral movement of the assessing fingers will help you in this, disguising arterial movement while assisting in feeling the artery.
To assess ease of pulse occlusion, the fingers are placed at the three traditional pulse positions and finger pressure is gradually increased over the radial artery until pulsations can no longer be felt. This is held for five seconds. There are two subcategories for ease of occlusion:
• Easy to occlude: A pulse that is classified as easy to occlude requires little pressure exerted on it to halt the pulsations, with either the arterial walls easily compressed or the arterial pulsation being easily stopped. The level of depth at which the pulsation can be felt strongest does not affect pulse occlusion. That is, both superficially and deeply located pulses may be easily occluded.
• Difficult to occlude: Significant pressure is required to occlude the pulse, equal to the pressure that is needed to palpate to the deep level. In some cases, the pulse may be still felt under the fingers. Sometimes the pulse can still be felt at the side of the proximal side of the ring finger. This is seen as an indicator of pulse strength
7.3.3.3. Interpretation of findings
When arterial wall tension is increased above normal, the artery feels very distinct and can still be clearly felt under the fingers when pressure is applied into the deeper levels of depth. In the extreme case it is even difficult to indent the arterial wall at the deep level of depth. At the other extreme, a lack of tension often means that only a pulsation can be felt; there is no evidence of the arterial wall. In this situation when the fingers are moved from side to side on the wrist where the artery is situated, only the soft skin of the wrist can be felt; there is no indication of the artery. Of course, between these two extremes there is a range of degrees of arterial tension.
7.3.3.4. Normal levels of arterial tension
Ideally, some tension in the arterial wall is required for a pulse to be classified as healthy. Such a phenomenon is due to sympathetic vasomotor tone, which will be discussed in more detail shortly. When considered healthy, arterial tension should be felt so that there is a distinct ‘impression’ of the arterial wall so that the width can be ascertained, but it is not ‘hard’.
7.3.4. Regulation of arterial tension: CM perspective
From a CM perspective, arterial tension is particularly related to Yang Qi. Therefore factors that affect Yang Qi affect arterial tension. Variations in arterial wall tension may arise as a result of hyperactivity of Yang Qi due to obstruction or stasis, vacuity of Yang Qi or damage to Yin fluids, or as the result of emotional stress.
7.3.4.1. Role of Yang Qi
Pulse tension depends on the functional state of Yang Qi. Lu (1996: p. 109) quotes from the Nei Jing ‘When Yang Qi functions normally, it can maintain the flexibility of the tendons and vessels.’ This is explained further, that arterial tension increases when Yang Qi is hyperactive and decreases when Yang Qi is deficient. A good example of this is the Stringlike (Wiry) pulse that results from a hyperactivity of Liver Yang Qi. Conversely, when Yang Qi is deficient the arterial wall may be difficult to feel clearly, as in the Scattered pulse.
7.3.4.2. Effect of Yin and Blood deficiency on arterial tension
Both Yin and Blood, as a Yin fluid, not only act as carriers for Qi but also have a balancing, cooling and nourishing effect on Yang, allowing it, among other responsibilities, to maintain the normal tension in the arterial walls. If that harmonising effect is impaired through loss of Yin (in numerous ways such as acute or chronic loss of blood or body fluids through sweating, vomiting or diarrhoea) then this may have a number of effects on the pulse. In the case of arterial tension, Yang Qi becomes relatively hyperactive, leading to an increase in arterial wall tension.
7.3.4.3. Emotions and arterial wall tension
In CM, emotional stress is considered to be a major cause of disease due to the flow-over effect on the physical body. The expression of a range of emotional responses is considered to be a healthy part of the normal psyche, but if any of these becomes prolonged or excessive in nature, or is not expressed freely, this may have an adverse effect on the individual’s health. Most commonly this may affect the normal flow of Qi, which, if sustained, may lead to problems of Qi stagnation.
In particular, the Liver is susceptible to emotional disturbance, particularly anger or frustration or the inhibition of emotional responses. As the Liver has a vital role in maintaining the free flow of Qi and consequently blood, factors impacting on the Liver may also affect arterial tension.
7.3.5. Regulation of arterial wall tension: biomedical perspective
The nervous system is responsible for controlling general blood flow to different regions of the body, heart activity and arterial blood pressure regulation as discussed by Guyton & Hall (2006: pp. 204-215) in Chapter 18. It does so via the autonomic nervous system in which the sympathetic nervous system plays an integral role. Most of the blood vessels in the body (except the capillaries, precapillary sphincters and metarterioles) are innervated via sympathetic vasomotor nerve fibres that leave the spinal cord through the thoracic and upper two lumbar spinal nerves. These enter the sympathetic chain and then travel to the heart and viscera via specific sympathetic nerves, or travel through the spinal nerves to the blood vessels at the periphery of the body. Higher control from the vasomotor centre located in the medulla and pons of the brain transmits sympathetic impulses to the blood vessels around the body and parasympathetic impulses to the heart via the vagus nerves (Guyton & Hall 2006: p. 206). Blood flow is regulated via vasoconstriction or vasodilatation of the blood vessels (Box 7.2).
Box 7.2
Effects of the autonomic nervous system on blood flow
• Increased sympathetic activity increases heart rate and strength of cardiac contraction
• Increased parasympathetic activity decreases heart rate, but the effect on heart contractility is only minor.
7.3.5.1. Sympathetic vasoconstrictor tone
The perceived ‘hardness’ of the radial arterial wall relates to the tone of the vascular smooth muscle in the tunica media of the blood vessels wall and is influenced by the nervous system’s effect on the contraction and expansion of the arteries (Lu 1996: p. 179). (See Fig. 2.5 for layers of the muscular arteries.)
Under normal conditions there is a ‘partial state of contraction in the blood vessels, called vasomotor tone’ caused by the vasomotor centre in the brain sending continual signals to the vasoconstrictor nerve fibres systemically. This helps to maintain pressure within the arterial system (Guyton & Hall, 2006: p. 206).
7.3.5.2. Alternative mechanism for increased arterial wall tension
The distinctness of the arterial wall is not always due to vasoconstriction. The Scallion Stalk pulse and the Drumskin pulse are examples of pulse qualities that have a distinct arterial wall that is not due to increased vascular smooth muscle tone. The maintenance of a distinct arterial wall such as that perceived in the Scallion Stalk and Drumskin pulses in the presence of vascular smooth muscle relaxation causing vasodilatation (as a consequence of compensatory response to blood loss) may be explained as follows. Kelly & Chowienczyk (2002) state that in muscular arteries such as the radial artery, decreased vascular smooth muscle tone usually leads to increased compliance (the ability to accommodate large volumes with little increase in arterial pressure). As vessel diameter increases, compliance usually does too. However, this does not always happen. Sometimes very large decreases in vascular smooth muscle (i.e. in a fully relaxed state) may result in the stress being transferred to other rigid components of the arterial wall and this then leads to decreased compliance. This may hypothetically explain the appearance of the Scallion Stalk or Drumskin pulses so that even though the arterial diameter is increased (signifying vasodilatation and therefore relaxation of the smooth muscle) the arterial wall still has increased definition.
7.3.5.3. Effects of febrile conditions and the shiver reflex
Febrile disease (caused by factors such as bacterial infection, environmental conditions, dehydration or tissue damage) has an effect on the temperature control centre in the hypothalamus, resetting the body temperature to a higher than normal value (Guyton & Hall 2006: pp. 898-901). As a result, the current body temperature is now below the new set point so a number of mechanisms are activated to help raise the body temperature to the new level. They include skin vasoconstriction, thyroxine secretion and sympathetic nervous system effects to increase cellular metabolism. During this time the individual usually feels very cold, the skin is cold because of vasoconstriction and this stimulates shivering which is experienced as ‘chills’. The shivering reflex increases the tone of the skeletal muscles throughout the body.
Hypothetically, the combination of the sympathetic effects on the blood vessels, causing vasoconstriction, in conjunction with the increased muscular tone, may result in increased radial arterial wall tension. This may explain why the Tight pulse is described as appearing in acute conditions such as an attack of EPA of Cold, accompanied by fever and chills.
7.3.5.4. Arterial tension and hypertension
From a biomedical point of view, the specific cause of primary hypertension is largely unknown, with a combination of genetic and environmental factors thought to be responsible for its progression according to Brashes (Chapter 30 in McCance & Huether 2006: pp. 1086-1092). It appears that a number of factors may lead to increased blood volume and increased peripheral resistance including overactivity of the sympathetic nervous system (increased vasoconstriction and cardiac output), overactivity of control of vascular tone and defects in excretion of sodium by the kidneys, leading to increased water retention and therefore increased blood volume. As the cardiovascular system attempts to deal with the increased blood volume, cardiac output increases, then regulatory vasoconstriction occurs. Blood volume remains high and as a result the increased peripheral resistance leads to increased arterial pressure, hence hypertension.
The vasoconstriction of the systemic arteries and resulting increased peripheral resistance may explain why increased arterial wall tension is considered to appear in hypertension, with some authors citing the Stringlike (wiry) pulse or the Tight pulse as occurring in this condition (Maciocia 2004, Wiseman & Ellis 1996). Researchers at the First PLA Medical University, Guangzhou found that ‘Most patients suffering from coronary heart disease have stringlike pulse due mainly to disorder of cardiac function, lowered arterial compliance and increased total peripheral resistance’ (Chen, Lin, Meng et al 1996). Utilising a combination of manual palpation to identify possible CM pulse qualities and biomedical cardiac function indices, they found generally that the coronary disease group were assessed as having ‘taut pulses’ (113 out of 120 cases) as well as having decreased myocardial contractility, stroke volume, left ventricular and arterial compliance, impaired left ventricular function and increased total peripheral resistance. It was surmised that the formation of the Stringlike (Wiry) pulse was due to a combination of factors such as arteriosclerosis, decreased vascular compliance and increased peripheral resistance. While the majority of patients were considered to have ‘taut pulses’ it appeared that these tended to appear in combinations with other CM pulse qualities such as Slippery, Slow, Thready and Rapid. However, there was no further breakdown of the group into subcategories. In addition, no concrete definition was provided for the term ‘taut’ and this seems to have been used interchangeably with the term ‘stringlike’.
The Guangzhou College (1991) notes explain that the mechanism of the taut (Stringlike) pulse may be due to increased vasoconstriction or increased blood volume or a combination of both, caused by arteriosclerosis which leads to increased arterial pressure and peripheral vascular resistance.
7.3.5.5. Arterial tension versus arterial hardening
The distensible nature of the vascular system refers to the ability of the arteries and veins to expand and accommodate pressure changes: both those associated with normal moment-to-moment changes with heart contraction and long-term pressure changes with hypertension and hypotension. This reflects the body’s normal ability to respond to the nervous system’s signals for vasoconstriction or vasodilatation.
As discussed by Brashers (Ch. 30 in McCance & Huether 2006: pp. 1086-1092), factors such as arteriosclerosis can affect the stiffness of arterial walls impacting upon their ability to dilate or constrict. Arteriosclerosis is caused by thickening and hardening within the arterial wall with eventual narrowing of the arterial lumen. While perhaps due to normal aging, it may also play a role in hypertension and other circulatory disorders. Atherosclerosis is an inflammatory pathological change to the arterial system that results in the laying down of fatty plaques in the walls of the medium-sized and large arteries. This has effects on blood flow via a decreased lumen due to the presence of atherosclerotic plaques and other changes to the arterial wall. It plays a major role in coronary artery disease and cerebrovascular disease (stroke) by causing obstruction to blood flow. However, it has been noted by O’Rourke et al (1992: p. 98) that despite the obstructive effects on the coronary and cerebral blood vessels, it appears that atherosclerosis has ‘little effect on the transmission of the pulse over long lengths of the aorta or other conduit arteries’ and the ‘contour of the brachial or radial arteries is rarely altered’.
7.3.5.6. Other factors influencing vascular tone
The ability of the vascular walls to dilate and constrict is influenced not only by the nervous system activity but also by substances that are actively produced by the endothelial cells lining the inside of the blood vessels. These substances play a role in influencing the tone and structure of the arterial wall and also influence its susceptibility to damage such as atherosclerosis. Nitric oxide (which causes vasorelaxation) and endothelin (a strong vasoconstrictor) are mediators produced by the endothelium and participate in the regulation of both basal vascular tone and blood pressure (Cockcroft et al 1997: p. 55). It is hypothesised that increased arterial stiffness may therefore result not only from physical changes to arterial wall structure due to ageing and arteriosclerosis, but also from endothelial dysfunction, affecting the availability of nitric oxide.
7.3.5.7. Ageing and arterial changes
Generalised degenerative changes to the arterial tunica media are responsible for arterial stiffness leading to changes in arterial pressure with age, and this is emphasised with arteriosclerosis (O’Rourke et al 1992: p. 98). Arteriosclerosis reduces arterial compliance and affects the ability of the arteries to expand and contract to the changing pressures during systole and diastole. The stiffening of the arteries occurring with ageing is distinct from that of atherosclerosis, which affects mainly the intimal layer of the artery wall.
7.4. Pulse occlusion
Pulse occlusion refers to the method of applying finger pressure to temporarily stop the pulsation in the radial artery by compressing it against the radius. Specifically, we use the term ‘ease of occlusion’ to refer to the amount of pressure that is required to halt the radial arterial pulsation. Additionally, this parameter encompasses whether pulsation can still be felt at the side of the ring finger once the pulsation has been occluded. This is usually indicative of a pulse that has force and signifies sufficient fluid in the vessel.
The parameter of pulse occlusion is not an actual component of the pulse, such as pulse rate, but rather is used as a diagnostic technique to provide further information about changes in other pulse parameters such as pulse force and arterial wall tension. Accordingly, pulse occlusion is used to further determine the overall strength of the pulse, relative fluid volume and the degree of tension within the arterial wall (Fig. 7.1). As such, it enables us to further differentiate between specific CM qualities that are defined by a number of other parameters.
 |
| Figure 7.1Schematic representation of variations in density of blood affecting tactile sensation of ease of occlusion. (A) ‘Normal’ blood viscosity. (B) Reduction in blood viscosity. |
7.4.1. Pulse occlusion: CM perspective
The parameter of pulse occlusion supplies information about the overall force of the pulse. However, this view is overly simplistic, as the ease with which a pulse is occluded is also influenced by other variables, including:
• The quality and activity of Yang Qi
• The volume of circulating fluids.
7.4.1.1. The quality and activity of Yang Qi
Yang Qi provides the motive force that initiates and sustains cardiac contraction, propelling blood through the arterial system. Yang Qi also plays a role in maintaining the normal tension of the arterial wall. Therefore, Yang Qi vacuity may result in a pulse that lacks force and/or has decreased arterial wall tension, resulting in a pulse that is easily occluded. Conversely, hyperactivity of Yang Qi may result in an increase in arterial wall tension and therefore the perceived ‘hardness’ of the arterial wall. The overall pulse strength and the volume of blood and Yin fluids may further influence this. For example, if Blood vacuity develops, then blood no longer cools the Liver, the Liver becomes hyperactive and overall Yang Qi is in relative excess resulting in an increase of arterial tension. In this situation, although tension is increased the pulse is relatively easy to occlude because of the underlying vacuity. There are two or three CM pulse qualities whose formation may be explained in this way.
The stronger the pulse wave the more difficult it is to occlude the pulse against the blood flow. Pulse force relates to both the relative activity of Yang Qi and the presence of sufficient Yin fluids to act as the medium to convey force. If Yin fluids diminish so too does pulse volume; accordingly, the loss of the carrier means that the force of the pulse is not transmitted through the vessels. The artery therefore becomes easier to occlude.
7.4.1.2. Volume of Yin fluids
Yin fluids refers not only to blood circulating in the arterial system but also to body fluids and Essence that reside in other areas of the body (see section 6.11.4.1 for futher information). These are involved in nourishing the organs, skin, muscle and joints and also in the maintenance of blood volume. As Clavey (1995: p. 13) notes, ‘In pathological situations, blood and jin ye fluids influence each other considerably’.
Therefore with blood loss, Jin Ye fluids can move into the blood vessels from the surrounding tissues to compensate for the fluid loss and replenish the blood volume, but not necessarily the quality of blood (there is no immediate regenerative effect on the loss of red blood cells). This has the effect of decreasing the viscosity of the blood (due to the loss of red blood cells, and therefore a greater proportion of plasma than usual). This may result in an artery that feels ‘empty’ (decreased density) and therefore more easily occluded.
Conversely, when there is a loss of body fluids, this can cause fluids from the blood to leave the blood vessels to help replace the lost body fluids. However, this leaves the ‘vessels empty and deficient, a condition known in TCM as “jin ku xue zao”: jin withered and blood parched. This can lead to severe Shen disturbance as the blood that would normally nourish the Heart becomes inadequate’ (Clavey 1995: p. 14). This also has the effect of increasing the viscosity of the blood (greater proportion of red blood cells than usual due to decreased plasma volume). As a result, this may result in the blood flowing less smoothly, due to increased resistance to the blood flow due to increased ratio of red blood cells to plasma (see Box 7.6).
Box 7.6
Body fluid loss versus Blood loss
From a biomedical perspective, the loss of either blood or body fluids (if severe, leading to hypovolemic shock) has a similar effect physiologically on the circulatory system by reducing cardiac output. Body fluid loss may occur due to excessive sweating, excessive urination or failure to replace lost fluids (inadequate fluid intake), while severe vomiting and diarrhoea can also affect both fluid and electrolyte balance. This loss of body fluid is known as dehydration.
In body fluid loss, plasma moves from the intravascular (inside the circulatory system) to the extravascular space to compensate for the lost volume. While this has a similar effect on the body’s autoregulatory mechanisms as a decrease in blood volume, there is an important difference:
• A decrease in plasma volume means that the viscosity of the blood is greatly increased due to the higher concentration of red blood cells and as such, results in sluggish blood flow (Guyton & Hall 2006: p. 285).
• Blood loss, on the other hand, results in a loss of both plasma volume and red blood cells, therefore the viscosity of blood will tend to decrease. This has the effect of decreasing the resistance to blood flow and increasing the flow rate, as thick fluids cause greater resistance to flow and move more slowly than thin fluids (McCance & Huether 2006: p. 1057).
7.4.2. Pulse occlusion: biomedical perspective
In biomedical terms, the degree of ease with which the pulse can be occluded is considered to be a function of pulse volume. The pulse volume is equated with pulse strength or amplitude, which is reflective of both stroke volume (the amount of blood expelled from each ventricle during systole) and peripheral vascular resistance (Estes 2006: p. 252). The pulse volume (perceived as the strength of pulsation) should be equal with each beat and should be palpable with moderate pressure, being able to be occluded with increased pressure.
Pulse volume is usually assessed via a three- or four-point scale ranging from absence of pulsation through to ‘bounding’ which is described as being ‘difficult to obliterate with pressure’ (Estes 2006: p. 254). Terminology that is commonly used to describe pulses with decreased volume includes ‘thready’ or ‘weak’, and these pulses are considered to be very easily occluded with light pressure, in accordance with the similarly defined CM pulse qualities (Box 7.3).
Box 7.3
Objective measurements of the pulse and ease of occlusion
In a study comparing objective measurements of the radial arterial pulse using applanation tonometry and assessment of the pulse using manual palpation, Walsh (2003) found a significant relationship for two tonometry measurements and the manual evaluation of pulse occlusion. These were PMaxPdt and peripheral systolic pressure (PSP) for the right hand.
The PSP reading was a measure of the maximum pressure exerted by the pulse wave in the radial artery during systole. For ease of pulse occlusion, the results indicated that high peripheral systolic pressure was associated with an increased difficulty in occluding the radial pulse by the pulse assessors using manual palpation (systolic pressure means below 120.2 mmHg for assessor 1 and 117.2 mmHg for assessor 2). Pulses that were selected as easy to occlude were associated with a low peripheral systolic pressure (means below 108.2 mmHg for assessor 1 and 107.7 mmHg for assessor 2).
PMaxPdt relates to the change in pressure with respect to time during systole. Walsh (2003) found that a greater mean value was associated with pulses selected as difficult to occlude (>700 mmHg/s) while a low value was associated with pulse selected as easy to occlude (< 600 mmHg/s). This indicates that the quicker maximum pressure is attained during systole (requiring the heart to contract strongly), the more likely the pulse was to be identified as being difficulty to occlude. This indicated a significantly shorter time to reach maximum pressure when the heart contracted for pulses rated as difficult to occlude compared to pulses rated as easy to occlude. Hence pulse force also has a bearing on ease of pulse occlusion.
The relationships as noted by Walsh (2003) must be viewed as a preliminary finding and as such need to be replicated in further studies with the possible investigation of CM descriptions of overall qualities described as easy to occlude, such as the Vacuous and Stringlike (Wiry) pulse, with specific disease states.
Changes in pulse volume from the norm can occur due to changes in either stroke volume or peripheral resistance. The pulse may be easily occluded if the circulating blood volume in the arterial system is decreased. Factors resulting in decreased stroke volume can include heart failure, cardiogenic shock leading to problems with heart contraction or decreased ventricular filling time due to problems with the heart’s conduction system.
Peripheral vascular resistance (PVR) is related to the ease with which blood flows through the circulatory system. Increased PVR (due to narrowing of the aorta or inflammation of the pericardium) may lead to a pulse with low amplitude that is easily occluded.
Conversely, the pulse may be more forceful than normal due to fever, infection, exercise, emotional anxiety or hyperthyroidism. Severe anaemia is also considered to be a factor causing a ‘bounding pulse’ due to the dual effect of decreased blood viscosity leading to decreased peripheral resistance and hypoxia (decreased oxygen to tissues) resulting in increased peripheral dilatation of blood vessels. These both lead to a greatly increased venous return to the heart and therefore greatly increased cardiac output (Guyton & Hall 2006: p. 236).
7.4.2.1. Factors affecting blood volume
As pulse volume is partially reflective of blood volume then factors affecting blood volume can also impact on how easily the pulse can be occluded. Blood volume can may be impaired as a result of:
Acute blood/plasma/body fluid loss
Blood/plasma loss may occur suddenly such as acute haemorrhaging due to trauma or gastrointestinal bleeding such as a perforated stomach ulcer. Fluid loss may occur due to excessive vomiting, sweating, diarrhea, dehydration or excessive urination. Hypovolemic shock is a type of circulatory shock that refers to the decreased blood volume resulting from blood or plasma loss. Circulatory shock causes inadequate blood flow around the body. There are usually three stages of circulatory shock (Guyton and Hall 2006: pp. 279-285, Tortora & Grabowski 2000, McCance & Huether 2006):
1. Nonprogressive (or compensated) shock: the body’s normal compensatory circulatory mechanisms are sufficient to eventually restore normal blood flow.
2. Progressive shock: certain positive feedback mechanisms occur to further weaken the heart and reduce cardiac output so the shock becomes progressively worse.
3. Irreversible shock: the further progression of shock until death.
From a CM perspective the different stages of hypovolemic shock may be the mechanism underlying the traditional CM pulse qualities such as the Faint pulse or the Scallion stalk pulse, relating to sudden acute blood loss (see individual CM pulse qualities for more information).
Chronic blood loss
Chronic blood loss may occur over time due to heavy menstrual bleeding, abnormal uterine bleeding, gastrointestinal bleeding, nosebleeds, hematemesis, hemoptysis, bleeding from haemorrhoids or cancer. Chronic blood loss may mean that blood loss is occurring at a faster rate than haemoglobin can be replaced, resulting in smaller red blood cells containing less haemoglobin (Guyton & Hall 2006: p. 426).
According to McCance & Huether (2006: p. 942)‘haemorrhage that is chronic (occult) produces adaptations that are less prominent and the individual experiences an iron deficiency anaemia when iron reserves become depleted.’
Insufficient blood production
Dietary restraints on eating sources of iron or the poor absorption of appropriate nutrients for the production of blood will also affect blood quality. While plasma volume remains unchanged, the number or size of red blood cells (RBCs) may be adversely affected, leading to a decrease in blood viscosity.
Each of the above situations impacts upon either the number of RBCs, plasma volume or haemoglobin-carrying capacity of the RBCs and therefore affects the circulatory system in varying degrees, hence the appearance of certain CM pulse qualities (see section 7.5.3.7 for more detailed information). These processes may be reflected within the CM pulse qualities such as the Fine, Faint or Scallion Stalk pulse qualities.
7.5. CM pulse qualities defined by arterial wall tension and ease of pulse occlusion
7.5.1. Stringlike (Wiry) pulse (Xián mài)
The Stringlike (Wiry) pulse is primarily defined by the physiological presentation of the arterial wall. Specifically, it is the high degree of arterial wall clarity that is of interest. The actual shape of the flow wave through the artery is a consequence of this increased tension in the radial arterial wall (Fig. 7.2).
 |
| Figure 7.2Schematic representation of the Stringlike (Wiry) pulse: Arterial tension constraining flow wave. The arterial wall is felt distinctly as a continuous length under all three fingers.(Adaptal from Figure 29.33 of McCance & Huether 2006 by permission of Elsevier Mosby.) |
7.5.1.1. Alternative names
In CM pulse literature the Stringlike (Wiry) pulse is most commonly called the Wiry pulse, but is also variously known as the Bowstring, Stringy or Strung pulse.
7.5.1.2. Requisite parameters
The Stringlike (Wiry) pulse is defined by changes to three pulse parameters:
• Arterial wall tension: The Stringlike (Wiry) pulse has increased arterial tension
• Length: The Stringlike (Wiry) pulse can be felt at all three traditional pulse positions and beyond Chi
• Pulse occlusion: With increasing finger pressure the arterial wall resists deformation, retaining its definitive shape.
7.5.1.3. Clinical definition
The Stringlike (Wiry) pulse has an increase in arterial wall tension and therefore the pulse wave cannot express its normal wave-like fluidity. Rather, it is the distinctness or tension in the arterial wall that inhibits the normal expansion and contraction response to the pressure and flow wave travelling through it. In this sense, it is not the pulse wave that defines the Stringlike (Wiry) pulse, but the actual physical structure of the arterial wall.
The arterial wall is perceived as rigid or dense due to the increased arterial tension, strongly resisting changes to its form when increasing finger pressure is exerted on it. Due to the increased smooth muscle tone in the arterial wall, the pulse is felt as a length of pulsation across the entire arterial segment at the wrist.
7.5.1.4. Identifying whether the Stringlike (Wiry) pulse is present
Step 1: This technique requires assessment of the ‘rigidity’ of the arterial wall (we are not actually concerned with the pulse wave at this time). Fingers are placed on the skin above the radial artery exerting light pressure moving repeatedly over the artery, medially and laterally (rolling side to side). (See Fig. 6.10 showing direction of movement of fingers across the width of the radial artery.)
Step 3: It is noted in the pulse literature that the Stringlike (Wiry) pulse retains its form when pressure is exerted on it: ‘stiff under the force of the fingers’ (Deng 1999: p. 143) and ‘press and it does not vary’ (Li, Flaws (trans) 1998: p. 100). The often repeated comparison of the Stringlike (Wiry) pulse with the wire string of a musical instrument also brings to mind the image of a pulse that retains its shape even with pressure exerted on it. In terms of the resilience of Stringlike (Wiry) pulse to deformation, two factors should be noted:
• The arterial wall resists deformation to finger pressure possibly even maintaining its shape as the deep level of depth is examined, although it can probably be occluded with sufficient pressure.
• From our experience, when pressure is released from the deep level of depth, the arterial wall quickly regains its original shape.
7.5.1.5. Levels of depth
The Stringlike (Wiry) pulse may be able to be felt at all levels of depth, but is usually strongest at the middle level of depth. However, pulse depth is not an essential component of the Stringlike (Wiry) pulse, rather it is the increased arterial tension. Where changes in both pulse depth and arterial tension occur concurrently, this may develop into a different CM pulse quality such as the Firm pulse which has increased arterial tension but is also found to be forceful and wide at the deep level of depth. Such a pulse type has a different pathogenic mechanism to that of the Stringlike (Wiry) pulse and therefore a different physical presentation.
7.5.1.6. Classical description from The Lakeside Master’s Study of the Pulse
The bowstring pulse is level and straight like the long [description from the Su Wen].
It is like a drawn bowstring [description from the Mai Jing].
Press and it does not vary …
Its shape is like the strings of a zither [description from the Mai Jue].
Passing through, straight and continuous,
It is stiff under the fingers’
7.5.1.7. CM indications
The Stringlike (Wiry) pulse primarily reflects pathology relating to constrained Qi, particularly involving the Liver. This may be transient, reflecting acute stressful situations, or may be indicative of chronic constraint of Qi and consequently associated with pathology. This is termed Qi stagnation and is commonly associated with the Liver. Other CM patterns that can be associated with obstruction of Qi include the presence of pathogenic factors such as Phlegm or Damp. Pain is also usually the result of Qi or Blood stasis (stagnation), so the Stringlike (Wiry) pulse can occur in any condition accompanied by pain.
Liver disharmonies
The Liver is traditionally associated with assisting the free spread of Qi throughout the body, and its movement is considered to have an expansive nature. In addition, the Liver has a major role to play in the storage of blood, providing sufficient blood to circulate through the blood vessels and channels, while returning at night to be stored in the Liver. The patterns of disharmony associated with the Liver therefore involve obstruction of this normal free flow and spreading of Qi and blood.
Liver disharmonies associated with the Stringlike (Wiry) pulse include Liver Qi stagnation, Liver Yang rising, Liver Fire, internal Liver Wind and Liver Blood stasis (Box 7.4).
Box 7.4
Signs and symptoms associated with Liver/gallbladder disharmonies
These depend on the exact Liver pattern but may be associated with the following:
• Irritability, anger, frustration, depression
• Rib or flank pain
• Sighing
• Flatulence
• Pellet-like stools
• Sore, red eyes
• Bitter taste in the mouth
• Muscular problems such as cramping
• Clinical relevance: Liver patterns can often be seen in patients suffering from emotional stress of some type or actual liver or gallbladder disease. The Stringlike (Wiry) pulse can also result from painful conditions of liver or gallbladder origin such as cholecystitis.
• Mechanism: The Liver is responsible for allowing the smooth circulation of Qi and therefore Blood throughout the body. Liver Qi is easily affected by emotions such as anger, irritability, resentment or the suppression of emotional stress, obstructing Qi flow.
Yang Qi is responsible for maintaining the normal tension of the arterial wall. If Liver Yang becomes hyperactive this can lead to increased tension in the pulse.
Phlegm or Damp
A number of authors agree that the Stringlike (Wiry) pulse can be seen in Phlegm patterns (Deng 1999, Li (Flaws trans) 1998, Lu 1996, Lyttleton 2004, Maciocia 2004). Phlegm is formed by a number of different processes (see Clavey (1995) for a comprehensive discussion on the aetiology and symptomatology of Phlegm) and may occur due to Heat or Fire within the body, causing body fluids to dry up and congeal. Alternatively, Liver Qi stasis can eventually turn to fire, again drying fluids. Flaws (1997: p. 53) describes Yin obstruction (due to Damp, Phlegm, food or blood causing obstruction or stasis) as being capable of impeding the free flow of Qi.
Phlegm/Damp is able to enter and ‘choke the circulation both inside and outside of the blood vessels’ (Clavey 1995: p. 177) impeding the flow of blood. This can be equated with hypertension in a biomedical context, where there is sclerotic loss of vascular elasticity and therefore increasing hardness of the arterial wall.
Clinically this can be seen in conditions such as epigastric fullness, nausea, vomiting, coughing with production of phlegm. Phlegm/Damp may also result in gynaecological problems such as amenorrhoea and infertility and this may present as a Stringlike (Wiry) pulse, particularly if Liver Qi stagnation is the contributing cause (Lyttleton 2004).
Pain
The Stringlike (Wiry) pulse may be seen in any condition where there is pain. From a CM perspective, pain indicates obstruction of Qi or blood or both. Therefore the lack of free flow is reflected in the increased arterial tension in the pulse. Pain evokes a systemic response, activating the sympathetic nervous system. This will tend to override other pulse variables, with increased arterial tension the predominating change in pulse parameters. Clinically, this pulse may be seen in abdominal or epigastric pain, dysmenorrhoea, headaches and musculoskeletal problems, irrespective of the cause.
Liver attacking the Spleen
Rogers (2000) describes this pattern as Wood energy attacking Earth energy, while Lu (1996) and Deng (1999) briefly mention the pattern of Liver encroaching on Spleen due to an underlying vacuity of the Earth energy. The aetiology is premised on the Five Phase (Wu Xing) arrangement of the organs involving the Ke cycle. The Ke cycle is the controlling cycle and within this cycle the Liver is responsible for keeping in check the functions of the Earth, particularly the Spleen. When the Spleen and Stomach Qi become deficient, or the Wood overexerts its controlling function, this results in digestive problems that present with both Wood and Earth type symptoms. For example, irritable bowel syndrome presenting with alternating diarrhoea and constipation and exacerbated by stress is a classic presentation of the Wood attacking the Earth pattern. Flaws (1997) suggests that a commonly seen pattern is Liver Qi stasis, occurring in conjunction with both Spleen damp and Blood vacuity.
Malaria
A number of authors (Li, Flaws (trans) 1998, Deng 1999, Lu 1996) describe malaria as presenting with a Stringlike (Wiry) pulse. Malaria is a febrile condition and in CM is usually recognised as having an exogenous Cold origin that has entered the body and is located between the interior and exterior. This is equivalent to the Shao Yang stage of Six Divisions (associated with the Gallbladder and Triple Energiser channels). Typical symptoms include fever, chills and severe headaches.
7.5.1.8. Does the Stringlike (Wiry) pulse occur in vacuity patterns?
The Stringlike (Wiry) pulse, in its true form, usually occurs in replete (excess-type) patterns. This is not to say that increased arterial wall tension does not occur in response to Yin or Blood vacuity. Flaws (1997) advises that the Stringlike (Wiry) pulse may evolve as the result of Blood vacuity, which affects the Qi by removing its ‘moisture and nourishment’. This, in turn, affects the free flow of Qi, leading to stagnation.
A number of pulses that reflect Blood vacuity do in fact present with increased tension, but these are not necessarily the definitive Stringlike (Wiry) pulse. If Blood vacuity occurs, then one might expect accompanying changes in other pulse parameters refecting the underlying vacuity pattern (such as a decrease in pulse force or change in width) and consequently the formation of another CM pulse quality, for example the Scallion Stalk pulse.
7.5.1.9. Clinical relevance of arterial wall tension
Although the Stringlike (Wiry) pulse in its extreme form may not always be present, there are many instances in which increased arterial wall tension may be identified in the pulse. Rather than trying to fit such a pulse into a certain CM pulse quality definition, and risk disregarding changes in other pulse parameters by doing so, we need to understand what the increase in arterial tension actually means in terms of pathogenesis.
Increased arterial tension may be construed as resulting from obstruction or stasis of Qi and/or blood, remembering that this may have a number of differing causes. This may seem overly simplistic, but it should be remembered that this information should then be incorporated into the bigger picture with the diagnostic information obtained from other aspects of the pulse and the other diagnostic techniques. The example used in the above section on Blood vacuity is a prime example of this. If the pulse information were underutilised to identify the pulse solely as the Stringlike (Wiry) pulse, then information regarding the underlying vacuity (represented by the ease of pulse occlusion in conjunction with the lack of force) would be lost.
7.5.1.10. Increased arterial wall tension as a reflection of stress
An increase in arterial tension in the pulse may be a normal transient response to stressors. This can be seen in the ‘fright, flight or fight’ response due to the release of epinephrine (adrenaline) and norepinephrine (noradrenaline) mediated through the sympathetic nervous system. CM would see this as a pathological type quality, but it could also be seen as a normal response to an acute situation. Stress in this situation is not considered an adverse reaction, but as an effective mechanism for allowing us to cope with increased demands on the body whether due to physical, emotional or psychological factors. A similar situation is seen in the body’s response to pain. In the pulse literature, the pulse qualities often associated with pain have as one of their main defining characteristics, an increase in arterial wall tension, for example the Tight or Stringlike (Wiry) pulses. In this regard, pain is seen as a stressor in the body.
Stress only becomes a problem if this tension remains after the stressor has passed, or if this type of stress becomes chronic. Clinically, if stress occurs – for example preparing for an exam or meeting deadlines at work – then the temporary stress is seen as a useful motivating force, rather than something to be treated. It is when the stress affects the body’s ability to be productive or to continue with normal activities, or when stress becomes chronic, that intervention is required. In these cases, levels of cortisol are consistently raised. Cortisol – one of the glucocorticoids produced by the adrenal cortex, useful in helping the body’s resistance to stress by increasing the production of ATP (used to produce energy) – makes the blood vessels more sensitive to substances that have a vasoconstrictive effect, which means that it effectively raises blood pressure (Tortora & Grabowski 2000). This is effective if the stress is due to blood loss; however, if it is not and this is happening consistently, then the increased blood pressure may have potentially harmful long-term effects on the heart and circulatory system.
7.5.2. Tight pulse (J
n mài) 
n mài) The Tight pulse is a complex pulse quality that is defined primarily by the effect of increased arterial wall tension on the pulse wave.
7.5.2.1. Alternative names
The Tight pulse is also known as the Tense, Intent, Taut or Squeezed pulse.
7.5.2.2. Requisite parameters
The Tight pulse has changes in four pulse parameters:
• Arterial wall tension: The Tight pulse has increased arterial tension.
• Force: There is an increased intensity of pulsation, so that this is a forceful pulse quality.
• Width: The arterial width is increased, so that it is perceived as a wide pulse.
7.5.2.3. Clinical definition
The Tight pulse, as its name implies, has a decrease in the elastic properties of the arterial wall so that is less able to expand and contract smoothly in response to the pressure and flow waves produced by the contraction of the heart. This is felt as an increase in arterial tension, so that the arterial wall is perceived as ‘hard’. The pulse displaces a wide surface area laterally across the finger, being perceived as having a wide arterial diameter. The pulsation hits the finger with increased intensity, and is therefore classified as a forceful pulse.
Although there are no direct references to the length of the Tight pulse, it is often likened to the Stringlike (Wiry) pulse (Li, Flaws (trans) 1998, Lu 1996, Wiseman & Ellis 1996) which is commonly described as long. Additionally, the descriptions often infer length and increased width by equating the Tight pulse with a rope or cord.
While increased width, length and tension are also invoked by the description of ‘vibrates to the left and right like a tightly stretched rope’ (Li, Huynh (trans) 1981: p. 18), this description also gives rise to what is considered to be, by some authors, the distinguishing feature of the Tight pulse; the slight lateral or sideways movement of the artery under the palpating fingers. This is surmised as occurring due to the heightened degree of increased arterial wall tension; the pressure pulse wave causes the artery to ‘vibrate’ or ‘contort’ side to side (left to right) due to the arterial wall’s inability to absorb and transmit the pulsatile force readily.
7.5.2.4. Confusion over pulse descriptors
There is some confusion in the CM literature over the actual presentation of this pulse quality. While some texts mention a side to side or left to right movement, much of the literature tend to also reiterate the traditional pulse descriptions which describe its similarity to feeling a ‘tightly twisted’, ‘taut’ or ‘tensely drawn’ rope (Deng 1999, Flaws 1997, Kaptchuk 2000, Lu 1996, Wang, Yang (trans) 1997).
Review of the pulse literature reveals that the Tight pulse is generally considered to be a forceful pulse. Li (Flaws trans 1998: p. 93) describes the Tight pulse as ‘left and right, pellet-like to the human hand’. The term ‘pellet like’ is defined earlier in the same text in another pulse definition as being round and hard, but not short. It is also described in the Mai Jing (Yang (trans) 1997: p. 3) as feeling ‘irregular like a turning rope’. Deng (1999: p. 128) utilises a number of different references, which again address the rope metaphor. However, the idea of an irregularity in form, not rhythm, is also raised, with additional descriptions of the pulse ‘with pressure it is like rolling, not even, but with bumps’ and reinforced by the likeness of the Tight pulse to a cord composed of a number of different threads twisted together. There are at least three possible interpretations here: one referring to the physical imperfections of the arterial wall; another to the action of the pulse wave due to the greatly increased tension of the arterial wall causing the artery to appear to slightly ‘shake’ or ‘vibrate’ sideways; thirdly, to the actual slipping of the artery from under the fingers due to the heightened arterial tension.
7.5.2.5. Identifying whether the Tight pulse is present
The Tight pulse is formed due to the increased arterial wall tension, which affects how the pressure and flow wave travels through the radial artery.
Step 1: The main feature of the Tight pulse is the significantly increased arterial wall tension, resulting in a tautness that can be felt under the palpating finger. The increased rigidity of the arterial wall results in either: the pressure wave causing the artery to move sideways as it passes through the artery or the artery moves sideways when finger pressure is applied, slipping away from the tips of the fingers.
Step 2: When assessing pulse force, the pulsation hits the fingers with increased intensity, and the artery resists deformation with increasing finger pressure.
Step 3: The pulsation is felt across a broad surface area of the palpating fingers and is therefore defined as wide.
7.5.2.6. Differentiating the Tight pulse from similar CM pulse qualities
There are a number of CM pulse qualities that have increased arterial wall tension. However, these are further distinguished by differences in other pulse parameters and accordingly these changes reflect the underlying pathogenesis (Table 7.1).
| -:not a requisite pulse parameter for this CM pulse quality. | |||||
| Tight pulse | Firm pulse | Stringlike (Wiry) pulse | Drumskin pulse | Scallion Stalk pulse | |
|---|---|---|---|---|---|
| Arterial tension | ↑ tension | ↑ tension | Significantly ↑ tension | Significantly ↑ tension | ↑ tension |
| Response of arterial wall to degree of tension | Arterial wall very distinct, ↑ tension causes slight sideways movement | Arterial wall very distinct | Arterial wall very distinct | Very taut on palpation | Can feel arterial wall distinctly |
| Pulse occlusion | Retains form with increasing finger pressure due to increased internal resistance within artery. | Retains form with increasing finger pressure due to increased internal resistance within artery. | Retains form with increasing finger pressure due to increased internal resistance within artery. | Retains form with increasing finger pressure but with heavy pressure, the pulse is easily occluded due to the lack of internal resistance (decreased volume) | Retains form even when pulse is occluded but rather than being rigid, it has a pliable arterial wall. |
| With significant pressure, pulse is occluded. | With significant pressure, pulse is occluded. | With significant pressure, pulse is occluded. | The pulsation is easily occluded due to the lack of internal resistance (decreased volume) | ||
| Arterial width | ↑ width | ↑ width | – | ↑ width | ↑ width |
| Pulse length | Long | Long | Long | – | – |
| Pulse force | ↓ force | ↑↑ force | – | ↓ force | ↓ force |
| Pulse depth | – | Deep level of depth | − | Superficial level of depth | Superficial level of depth |
| Pathogenesis | Pain, food retention, EPA cold or internal cold | Internal cold, internal obstruction due to Qi or Blood stasis and pain | Qi stagnation LV/GB disharmony phlegm/damp malaria pain | Yin vacuity complicated by EPA cold acute profuse Yin fluid loss severe Yin & Essence vacuity | Loss of Blood or Yin fluids (acute or chronic Blood vacuity) |
The five CM pulse qualities listed in Table 7.1 all present have increased arterial present wall tension. The Scallion Stalk pulse and Drumskin pulse are easily occluded with pressure, whereas the Stringlike (Wiry) pulse clearly retains its form. The Firm pulse has a similar pathogenic mechanism to the Tight pulse, in relation to the presence of pathogenic Cold. In this sense, the Firm pulse and the Tight pulse are interrelated and the Firm pulse could be considered a variation of the Tight pulse but located at the deep level, reflecting the invasion of pathogenic Cold moving directly into the interior. The Tight pulse and Firm pulse have similar changes in pulse parameters and therefore may present in a similar fashion; however, the Firm pulse is always found to be relatively strongest at the deep level of depth. This specifies the location of the disease, which is at the internal level and also reflects the inability of Yang Qi to move outwards due to obstruction, shown by the increased arterial tension. In addition, the Tight pulse as an increase in arterial tension such that the artery gives the impression of slightly moving side to side as a result of the pulse wave moving through the constricted arterial wall.
7.5.2.7. Classical description from the Mai Jing and The Lakeside Master’s Study of the Pulse
The tight pulse is an inflexible pulse like a tensely drawn rope [said in another version to feel like a turning rope]
The tight pulse comes and goes with force.
Left and right, pellet-like to the human hand. Su Wen)
7.5.2.8. CM indications
It is commonly understood that the Tight pulse is indicative of pain. Pain arises from the obstruction of Qi and/or blood flow. With the Tight pulse, Cold is considered the primary cause of pathogenesis in the pulse literature. This is attributed to the contracting nature of Cold, which is seen as having a constricting effect on the arterial wall. Therefore the Tight pulse can be seen in disharmonies relating to stagnation of Qi and/or blood commonly due to pathogenic Cold, usually presenting with pain as a primary symptom. However, the Tight pulse may be seen in any painful condition due to obstruction of the normal flow of Qi and blood. The four patterns associated with the Tight pulse are:
• Pain
• Internal Cold
• EPA of Cold
• Food retention
Pain
Pain is a common symptom associated with obstruction of Qi and/or blood flow. The associated signs and symptoms will depend on the location of the pain and the specific organ affected. The nature of the pain, for example sharp, distending, stabbing or dull, assists in identifying the pattern of disharmony.
Internal Cold (abdominal and pelvic regions)
Three organs are particularly vulnerable to direct invasion by pathogenic Cold: the stomach, the large intestine and the uterus (Maciocia 1989). This can result in strong pain due to the obstruction caused by the contracting nature of Cold on Qi and blood flow.
Clinically, the Tight pulse may be seen in conditions such as sudden stomach pain, abdominal distension and fullness, diarrhoea, loss of appetite or dysmenorrhoea (menstrual pain). Exposure to environmental cold or excessive consumption of cold, raw food such as ice cream, fruit, salad or cold drinks may contribute to the formation of this pulse. In women, exposure to Cold during menstruation, such as swimming or wearing inadequate clothing in cold weather, are also seen as potential causative factors (Lyttleton 2004: p. 17).
EPA of Cold (without abdominal symptoms)
This may be seen in an external invasion of Wind Cold and may occur following exposure to cold weather. Pathogenic Cold has a contracting effect on the blood vessels, causing an increase in arterial tension. As an EPA, it would be expected that the pulse would also be felt relatively strongest at the superficial level of depth, providing the body’s Zheng Qi is strong.
Clinically, this may be seen as an acute onset of a cold or flu-type viral infection. Common signs and symptoms include strong body aches, aversion to cold, chills and fever, no thirst or sweating and a sore throat.
Food retention
Food retention may occur when Stomach Qi is deficient or not descending properly or there is excessive food intake. This can cause obstruction of Qi and blood leading to pain, hence the formation of the Tight pulse.
7.5.2.9. Biomedical perspective
The over-distension of a hollow organ, such as the stomach, can result in pain either by overstretching the actual tissue or because the overfilling leads to compression of blood vessels supplying or surrounding the organ. This can lead to pain due to the reduced blood flow to the area (this is known as ischaemic pain) (Guyton & Hall 2006: p. 604).
Intestinal obstruction can occur within or outside the intestines, resulting from fibrous adhesions (postsurgical or from trauma), twisting of the part of the intestine, herniation, inflammatory intestinal disease or diverticulitis. This may lead to distension and pain, depending on the severity and location of the obstruction.
7.5.3. Scallion Stalk pulse (Kōu mài)
The main area of focus for the Scallion Stalk pulse is on the physiological presentation of the arterial wall and the manner in which it reacts to increased finger pressure, retaining its clarity and form.
7.5.3.1. Alternative names
Hollow, Onion Stalk, Leekstalk or Split pulse.
7.5.3.2. Requisite parameters
The Scallion Stalk pulse is a complex pulse quality with changes to five pulse parameters:
• Arterial wall tension: There is an increased arterial wall tension
• Depth: The Scallion Stalk pulse is found to be relatively strongest at the superficial level of depth
• Width: The arterial width is increased, resulting in a wide pulse
• Force: The overall pulse force is decreased in intensity
7.5.3.3. Clinical definition
Two components are involved in defining this pulse: the first relates to the arterial wall tension and the second concerns the pulse wave. There is a distinct and palpable arterial wall at both the superficial and deep levels of depth, reflecting an increase in the arterial wall tension. The pulse wave can be felt relatively strongest at the superficial level of depth, but there is an overall lack of intensity to the pulsation reflecting the underlying vacuity of blood. This means that when finger pressure is applied to the artery the pulsation is easily occluded.
It is the combination of the above two factors which creates the most distinguishing feature of this pulse; the wall of the artery can still be very distinctly felt even when the pulsation within the artery has been occluded. This results in being able to roll the fingers over the arterial wall under the palpating fingers, and ‘squash’ it, rather like flattening a plastic drinking straw. In this sense, it is not the pulse wave that defines the Scallion Stalk pulse, but the actual physical structure of the arterial wall that can be felt regardless of the pressure exerted on it.
This aspect readily reflects the traditional description of an onion or scallion stalk, indicating a distinct and pliable arterial wall but lacking in substance in the interior. In this case, the substance lacking is Blood. The metaphorical description of the pulse used extensively in the traditional literature in this situation is quite apt in conveying the actual sensation of the pulse as felt.
7.5.3.4. Identifying whether the Scallion Stalk pulse is present
Step 1: The Scallion Stalk pulse should be able to be felt with the fingers resting lightly on the surface of the skin, at the superficial level of depth. The pulsation is decreased in strength and the arterial diameter is relatively wide.
Step 2: This involves feeling for the physical characteristics of the artery wall. The arterial wall is well delineated, being able to be felt easily at the superficial level of depth, with fingers resting on the skin surface. When finger pressure is increased from the superficial level of depth downwards, the arterial wall compresses easily and the pulsation is stopped. However, the arterial wall can be easily rolled underneath the fingers, like squashing a plastic drinking straw, so that the walls are still distinctly felt under finger pressure. This requires moving the palpating fingers from left to right, over the arterial wall.
7.5.3.5. Classical descriptions from the Mai Jing and The Lakeside Master’s Study of the Pulse
The scallion stalk pulse is a floating pulse, large but soft. It is empty in the middle but solid at the sides when pressure is applied. [It is said in another version to be a pulse absent under directly under the (feeling) fingers but present at the sides.]
Centre is empty, external is replete [or real, i.e. it exists]
Its shape is like an onion stalk.
7.5.3.6. CM indications
The Scallion Stalk pulse is always considered a pathological pulse quality and is commonly associated with the loss of blood or Yin fluids (Box 7.5Box 7.6 and Box 7.7). While many authors agree that this is usually due to acute haemorrhage, others describe this pulse appearing due to chronic insidious blood loss, Blood vacuity patterns or in chronic illness affecting the haematological system, such as anaemia or leukaemia (Lu 1996).
Box 7.5
Blood vacuity signs and symptoms
• Pale white or sallow complexion
• Dizziness
• Floaters in the vision, also called ‘flowery vision’
• Pale lips, inner rim of the lower eyelid
• Pale nail beds
• Pale tongue, may have orange sides if severe
• Palpitations
• Dry skin
• Insomnia, particularly trouble falling asleep
• Numbness
• Poor memory
Specific signs and symptoms may differ according to the particular organs involved:
• Liver: Dry eyes, muscle cramping, menstrual problems
• Heart: Shen disturbances such depression or anxiety
• Spleen: Tiredness, loss of appetite
Box 7.7
Does profuse loss of body fluids lead to the formation of the Scallion Stalk pulse?
Besides blood loss, the profuse loss of body fluids is sometimes implicated in the development of the Scallion Stalk pulse (Maciocia 2004, Townsend & De Donna 1990). From a CM perspective, when body fluids are seriously depleted, fluids (plasma) from the blood can move from the blood vessels into other body tissues to replace lost fluids. From a biomedical pespective the loss of plasma volume results in a decrease in overall blood volume, and an increase in blood viscosity. The increased proportion of red blood cells adds extra resistance to flow as the red blood cells move against each other and the vessel walls. This extra friction causes the blood flow to become sluggish and therefore more turbulent. It is this characteristic of the blood flow that becomes the main defining aspect of the resulting pulsation. As such we could surmise that the Rough pulse, with its fluctuating pulse force reflecting the sluggish blood flow, will tend to manifest as a result of loss of body fluids, while the Scallion Stalk pulse reflects loss of blood.
Blood vacuity may be due to dietary causes, malabsorption problems or congenital conditions such as pernicious anaemia, thalassaemia or sickle cell anaemia. Anaemia is a complex disease state that can have a number of different causes, affecting both the presentation of the pulse and reflecting the underlying causal factors. Blood vacuity due to iron deficiency anaemia results in a decrease in the number or size of the red blood cells but no loss of plasma volume. This leads to a decrease in the viscosity of the blood that, with regard to the Scallion Stalk pulse, may partially account for the ease with which the pulse is occluded.
Other causes of Blood vacuity include blood loss through various means: vomiting blood (haematemesis), coughing up blood (haemoptysis), gastrointestinal bleeding, uterine bleeding or abnormally heavy menstrual bleeding. In this case both red blood cells and plasma are lost, resulting in a decrease in overall blood volume as well. In addition, the profuse loss of body fluids may also result in the formation of the Scallion Stalk pulse. There are two main patterns that can result in the formation of the Scallion Stalk pulse both reflecting Blood vacuity but due to different causes. These are:
• Acute: Blood loss due to haemorrhage
• Chronic: Chronic blood loss, vacuity of Blood or Kidney Essence.
Acute, following severe loss of blood (haemorrhage)
From a CM perspective, the acute loss of blood results in an artery that feels ‘empty’ due to the decreased volume of circulating blood and is therefore easily occluded. Yang Qi, which is normally anchored and stabilised by Yin blood, moves upwards and outwards causing the pulse to become strongest at the superficial level of depth. Yang Qi becomes relatively hyperactive, having lost the calming aspect of the Yin, leading to an increase in arterial wall tension. This leads to the distinctive arterial wall.
Major blood loss can lead to ‘Qi deserting with the Blood’ (Wiseman & Ellis 1996: p. 151) and may be accompanied by decreased blood pressure, cold sweats or even sudden loss of consciousness.
Chronic: vacuity of Blood or Essence
Vacuity of Blood can occur via the chronic loss of blood due to bleeding from the gastrointestinal tract (for example, ulcerative colitis, stomach ulcers, Crohn’s disease or coeliac disease), chronic nosebleeds, abnormal uterine bleeding, haemoptysis or blood in the urine. Although the daily loss may be small in quantity, consistent loss of blood may lead to the body being unable to produce enough blood (haemoglobin to compensate adequately for the continual loss.
Blood vacuity may also occur due to problems with the organs that are involved in blood production such as the Spleen, Heart or Kidneys, so that sufficient blood is not produced. As these organs are also important in the production of Qi, concurrent Qi vacuity signs and symptoms may be present. The Liver helps to replenish blood, so Liver disharmony may also affect the quality of blood.
Chronic illness of any kind can affect the production of both Qi and blood, so that blood and Qi are not replenished. Kidney Yin vacuity can lead to vacuity of Kidney Essence, which in turn affects blood production and nourishment.
7.5.3.7. Biomedical and clinical perspective
The Scallion Stalk pulse can present as a result of:
• Acute blood loss
• Chronic blood loss or reduced iron intake.
Acute blood loss
The Scallion Stalk pulse may be seen in patients following blood loss, usually due to an acute situation. This may result from physical trauma or non-trauma-related blood loss such as acute gastrointestinal bleeding, for example a perforated ulcer. This may cause hypovolemic shock, referring to the decrease in blood volume due to loss of blood (hypovolemic shock also refers to the loss of plasma that may occur due to severe burns, intestinal blockage or the excessive loss of body fluids due to profuse sweating, vomiting, diarrhoea or urination) (see Box 7.6 for further information).
The term ‘shock’ refers to ‘an inadequate cardiac output that results in a failure of the cardiovascular system to deliver enough oxygen and nutrients to meet the metabolic needs of body cells’ (Tortora & Grabowski 1996). As previously discussed in section 7.4.2, there are three stages of shock. The Scallion Stalk pulse may possibly arise following either a small amount of blood loss or with increased blood loss (Box 7.7).
If blood loss is less than 10% of total volume then this is known as nonprogressive shock and compensatory mechanisms are initiated in the period after the blood loss to return blood volume back to normal (see Box 7.8). This includes the absorption of fluids from the interstitial spaces and intestinal tract. Although this is helpful in increasing the plasma volume back to normal (which takes 1-3 days), it does not compensate for the loss of red blood cells, which may take 3-6 weeks to return to normal. Therefore, following nonprogressive blood loss the red blood cell concentration is low while plasma volume returns to normal fairly quickly. This results in posthaemorrhagic anaemia and may help explain why the pulsation is more easily occluded as the blood flow is less dense (lower proportion of red blood cells) and has a decreased viscosity (‘thinner’ in consistency). This has a number of effects: a decrease in peripheral resistance so blood flow is increased; peripheral vasodilatation to increase blood flow through the tissue because of decreased oxygen supply to tissues due to decreased red blood cell concentration. These both result in more blood returning to the heart and an increased cardiac output. This may cause the pulse to be more readily palpated at the superficial level of depth, have a wider diameter than usual and be more readily occluded.
Box 7.8
Body’s response to hypovolemic shock
Nonprogressive shock (compensated shock)
There are certain initial compensatory mechanisms that occur in response to hypovolemic shock to attempt to restore the body’s homeostasis, return cardiac output and arterial blood pressure to normal. This includes activation of the sympathetic nervous system and the release of the certain substances that increase heart rate, cardiac contraction and the secretion of certain hormones such as aldosterone and antidiuretic hormone (ADH) that help to retain water and increase vasoconstriction to increase blood volume and blood pressure. This process starts immediately and may continue up to 48 hours if necessary.
Some of the factors than come into play when there is blood loss include the following effects on the circulatory system (Guyton & Hall 2006: p. 279-281):
• Immediate (within 30 seconds): Sympathetic reflexes that cause vasoconstriction of vessels throughout the circulatory system.
• Within 10 to 60 minutes:
– Release of angiotension and vasopressin, substances that help to constrict peripheral arteries and veins to increase water retention by kidneys.
– A reverse stress-relaxation of the circulatory system causes the blood vessels to contract down around the decreased volume in order to make it fill the circulartory system more appropriately.
• Longer term (within 1 to 48 hours): Replacing the fluid loss via absorption from the interstitial spaces and intestinal tract and stimulation of thirst and increased desire for salt.
If blood loss is more severe, dropping by more than 15% of total volume, then the normal compensatory mechanisms are not sufficient and urgent medical intervention to replace fluids lost is required to return blood volume to normal. This is known as progressive shock, and cardiac output falls dramatically, which is worsened by the instigation of positive feedback cycles. Due to the decreased cardiac output, the heart muscle becomes ischaemic, leading to even lower output and blood pressure. This in turn adversely affects the activity of the vasomotor centre in the brain that controls vasoconstriction. This leads to generalised vasodilatation of blood vessels. The pulse is forceless due to the decreased cardiac output, the arterial width is increased due to vasodilatation and is easily occluded due to the lack of volume in the arterial system and hence, the Scallion Stalk pulse manifests.
The increased arterial wall tension that results in the distinctive pliable arterial wall of the Scallion Stalk pulse (as previously discussed in section 7.3.5) occurs due to tension in other parts of the arterial wall structure, not from contraction of vascular smooth muscle. In fact, the artery wall is in a state of vasodilatation because of the blood loss.
The Guangzhou College notes (1991) state that the Hollow (Scallion Stalk) pulse has been shown to appear experimentally when blood loss is both rapid and heavy (>400 ml) and when the usual compensatory reflexes of vasoconstriction have not resulted in strong contraction of the blood vessels (no specific research study has been cited).
Chronic blood loss or reduced iron intake
Chronic blood loss may result in anaemia, occurring over a period of time due to the body’s inability to absorb enough iron from the intestinal tract (mainly the small intestine) to replace the lost haemoglobin. This can result in the production of smaller red blood cells containing insufficient haemoglobin. A loss of 2-4 ml of blood per day is enough to cause iron deficiency anaemia (McCance & Huether 2006: p. 934). Chronic disease such as chronic inflammatory disease, HIV/AIDS, hepatitis and chronic renal failure may also result in anaemia due to alterations to iron metabolism, red blood cell life span, and blood cell production in the bone marrow (McCance & Huether 2006: Ch. 26).
Chronic blood loss may occur due to occult bleeding such as gastrointestinal tract bleeding from ulcers, inflammatory bowel disease, coeliac disease, carcinoma or a range of other gastrointestinal complaints. In addition, menorrhagia (heavy menstrual bleeding) or abnormal uterine bleeding may also contribute to blood loss.
Alternatively, there may be inadequate dietary sources of iron resulting in anaemia due to general decreased food intake, specific dietary restrictions (for example, restrictions on meat) or problems with iron absorption such as coeliac disease or other inflammatory intestinal disease.
As noted by Guyton and Hall (2006), anaemia has a systemic effect on the circulatory system. In anaemia, it is the lowered proportion of red blood cells to plasma volume that results in a decreased blood viscosity. This in turn has a positive effect on the peripheral resistance to blood flow, resulting in an increased amount of blood flowing through the tissues and returning to the heart. The increased blood flow to the heart results in increased cardiac output, which is further enhanced by vasodilatation of peripheral blood vessels due to decreased oxygen supply to tissues (hypoxia). The rate of blood flow also increases. In other words, the cardiovascular system, particularly the heart, has to work much harder to continue to supply the body with sufficient oxygen and nutrients and transport metabolic waste products to be eliminated.
Over time this can have a detrimental effect on the heart, leading to eventual cardiac failure if the underlying cause of anaemia is not addressed. In severe anaemia, the cardiac output may be raised to as much as three or four times normal levels (Guyton & Hall 2006: p. 427).
From a CM perspective, such physiological changes are represented in the pulse by:
• Increased pulse width due to both the peripheral vasodilatation and increased cardiac output
• Distinct presence of the pulse at the superficial level due to the increased cardiac output
• Easy occlusion due to the decreased viscosity and therefore density of blood flow (reflecting the underlying vacuity of blood).
Recent research has shown that Helicobacter pylori, bacteria commonly implicated in digestive dysfunction such as duodenal and stomach ulcers, may also lead to iron deficiency anaemia (Russo-Mancuso et al. cited in McCance & Huether 2006: p. 934). H. pylori has been shown to impair iron absorption (Ciacci et al. cited in McCance & Huether 2006: p. 934). This has an interesting correlation with CM theory, where impaired functioning of the Spleen and Stomach, integral to digestive functioning, can also lead to the impaired production of both blood and Qi.
7.5.4. Drumskin pulse (Gé mài) 
With the Drumskin pulse, it is the physiological characteristics of the arterial wall that are of primary interest, in particular the significant increase in arterial wall tension, in conjunction with the lack of force.
7.5.4.1. Alternative names
Leather, Tympanic, Leathery or Leather-like pulse.
7.5.4.2. Requisite parameters
The Drumskin pulse is a complex pulse quality with changes in five pulse parameters:
• Arterial wall tension: The Drumskin pulse has increased arterial tension
• Depth: The pulse can be felt relatively strongest at the superficial level of depth
• Width: There is an increase in the arterial width from normal, resulting in a wide pulse
• Pulse occlusion: The Drumskin pulse can be easily occluded with heavy pressure
7.5.4.3. Clinical definition
The Drumskin pulse has a wide arterial diameter, so a large surface area is displaced laterally on the fingertip with each pulsation. The Drumskin pulse has a greatly increased arterial tension so that on light palpation the arterial wall feels extremely tense and rigid. Given this, the arterial wall has strong initial resistance to light finger pressure, but with increasing pressure the pulse is easily occluded. This is facilitated by the decrease in blood volume. This also affects the intensity of the pulsation, resulting in a forceless pulse. The Drumskin pulse is felt as a length of pulsating artery, as opposed to distinct wave-like pulsations due to the effect of increased tension in the arterial wall.
When the Drumskin pulse is described in the pulse literature, it is commonly equated with both the Stringlike (Wiry) pulse and Scallion Stalk pulse. For example, Li (Flaws (trans) 1998: p. 103) describes the Drumskin pulse as ‘bowstring and scallion-stalk’ while Lu (1996) says the pulse is ‘felt hard on its walls but hollow in the centre’. Accordingly, we can surmise from this that the important features of the Drumskin pulse relate to:
• Increased arterial wall tension (a common feature of the Stringlike and Scallion Stalk pulse also)
• Decreased volume of either Blood or Yin fluids (common to both the Scallion Stalk pulse and Drumskin pulse), resulting in its forceless pulsation and easy occlusion.
The differentiating feature between the Drumskin pulse and the Scallion Stalk pulse is the degree of increased arterial wall tension: the Drumskin pulse has significantly more tension in its arterial wall, resulting in a more rigid and less pliable artery wall than the Scallion Stalk pulse. Additionally, unlike the Drumskin pulse, the distinct arterial wall is still felt in the Scallion Stalk pulse even when the pulsation within the artery is occluded.
The description and indications for the Drumskin pulse in The Lakeside Master’s Study of the Pulse are comparatively brief in relation to that of many of the other pulse qualities. This suggests that it only occurs in quite defined situations (as opposed to some of the other pulses that may be seen in a number of different scenarios) and therefore this pulse quality is not commonly seen.
There are also relatively few references to the Drumskin pulse in the Mai Jing and these are generally repeated throughout. The Mai Jing’s description of the Drumskin pulse is identical to more recent definitions of the Firm pulse, being ‘replete, large, and long as well as a little bowstring’ and somewhat like the deep pulse’. The commentary in the text notes that this is suspected to actually be the Firm pulse rather than the Drumskin pulse (Wang, Yang (trans) 1997: p. 4). If this is the case, the Drumskin pulse, in its current form, was not included as one of the 24 pulse qualities mentioned in the Mai Jing.
However, an examination of the Mai Jing (Wang, Yang (trans) 1997: p. 343) reveals a further reference to a pulse that is described as ‘bowstring and large’, further explained as ‘modulated bowstring’ (as opposed to ‘pure bowstring’) and ‘not so large as scallion stalk’. Pointing out that modulated bowstring indicates cold and scallion stalk means vacuity, the author notes the interaction of these two results in the pulse becoming ‘drumskin’. This description closely resembles the definition of the Drumskin pulse as it is known today. Pathogenic Cold has a contracting effect (that is, a vasoconstricting effect on the arterial wall) which may explain why it is described as being not as large (wide) as the Scallion Stalk pulse.
7.5.4.4. Identifying whether the Drumskin pulse is present
Step 1: The Drumskin pulse can be felt relatively strongest at the superficial level of depth, with fingers resting gently on the surface of the skin above the radial artery. However, of primary interest is the significant tautness of the arterial wall. The arterial wall is relatively wide, displacing a wide surface area of the palpating finger. The overall pulsation is forceless.
Step 2: With increasing finger pressure the arterial wall initially resists deformation, maintaining its tenseness. However, as finger pressure is further increased the arterial wall gives in easily, as there is decreased internal resistance within the artery due to the decreased volume of fluids. The pulsation can be completely occluded.
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Related posts:
Historical pulse records and practice
Issues of reliability and validity
Getting started: pulse techniques, procedures and the development of a methodical approach to pulse assessment
Other systems of pulse diagnosis
Genesis of pulse qualities
Simple CM pulse qualities and associated pulse parameters
