Overview

Several notable developments have occurred since the last edition of this textbook. Electronic repositioning in conjunction with bipolar leads (soon to be multipolar leads) has greatly improved success.²⁶ The most important development involves delivery systems.^27,28 Telescoping guide support–based delivery systems employ sliceable, preshaped guides for insertion through a separate coronary sinus (CS) access catheter that delivers leads directly to the target vein, allowing for interventional techniques.^29,30 Optimal use requires the physician to learn and apply such principles as safe use of contrast, manipulation of open-lumen catheters, effective and efficient injection of contrast, and importance of table position.³¹

Although an important advance, the new guide support–based delivery systems have two limitations: (1) most do not offer a delivery guide for leads with diameter of 6 to 7 French, and thus only leads 5 Fr (5F) or less usually are deliverable, and (2) most lack a vein selector. A vein selector serves two functions. First, it locates and cannulates the target vein. The design parameters required for a delivery guide, however, limit the ability to locate and cannulate the target vein. It is easier and safer to use a small catheter with a flexible tip to locate the target vein than a catheter designed to provide support for lead delivery. Second, the vein selector provides a rail for the delivery guide. Once the delivery guide locates the vein, it may not be possible to advance into the vein. If a small, flexible-tip catheter is telescoped into the vein through the delivery guide, it can be used as a rail to ensure the tip of the guide engages the vein. The small catheter with a flexible, tapered tip that telescopes through the delivery guide to locate the vein, then act as a rail over which to advance the guide, is a “vein selector” (Fig. 22-1).

Figure 22-1 Delivery guide advanced using vein selector and wire as rail.

A, Delivery guide is inserted into the coronary sinus (CS) through the CS access catheter, but will not advance into the vein over the wire. B, Vein selector is telescoped through the delivery guide and used to locate and cannulate the target vein. A wire is advanced into the vein, and the vein selector/wire is used as a rail over which to advance the delivery guide. The design of each component can be optimized for its specific purpose.

Although catheters from interventional radiology and cardiology can be used as vein selectors, they are the wrong length, the tips are too stiff, and the shapes are not ideal (Fig. 22-2). Fortunately, additional vein selectors are now available in multiple shapes (Fig. 22-3).

Figure 22-2 Variety of shapes used to locate and cannulate target veins over last decade.

(Courtesy Boston Scientific and AngioDynamics.)

Figure 22-3 Vein selectors.

Left to right, Impress Standard p/n 1628-Y8, Impress CS Vert p/n 1628-017, and Impress CS Hook p/n 1628-019. Vein selectors are used to locate, cannulate, and advance wires into the target vein, then provide a rail over which to advance the delivery guide. More than 90% of cases can be done with the Standard, which is included with all the Pressure Products delivery guides (SafeSheath Worley Series, Telescopic Series lateral vein introducers). The catheters are 5 French (5F) outer diameter (OD) and 75 cm long with soft, tapered tips. The CS Hook can be useful near the CS os and with other veins that have a very acute takeoff. The CS Vert is helpful when the takeoff is less acute but tortuous. The black distal section of the catheter is soft and can be easily straightened as the selectors are advanced over wires into the target vein. Thus, once the os of the vein is identified by a puff of contrast, the wire can be advanced, followed by the vein selector to add a second wire. The ability of the vein selector to be advanced deep into the vein over the wires allows creation of a stable rail over which to advance the delivery guide. The Merit Medical vein selectors can be used with the delivery guides provided by the device companies.

Philosophical Approach

This chapter employs the mindset that left ventricular lead implantation should use the most effective tools and techniques to succeed with a transvenous approach. Often this requires tools supplied by more than one vendor and multiple techniques. This approach puts the welfare of our patients first and increases the responsibility of the implanter. If the traditional transvenous approach fails, one option is transseptal, an approach that can be technically difficult and associated with the risk of thromboembolism.³² However, recent studies found a superior hemodynamic performance associated with endocardial compared with epicardial stimulation,³³ possibly by allowing access to previously inaccessible pacing sites.³⁴ Our experience in four patients who declined a surgical lead is favorable. Chapter 23 provides a more detailed discussion of transseptal LV lead placement.

Surgical epicardial LV lead placement is covered in the final section of this chapter. Although the surgical approach is an easy way for the implanting physician to complete the procedure,³⁵ “the importance of maximizing the use and safety of transvenous approaches is stressed because while the electrical and functional limitations of trans-CS LV epicardial coronary vein leads are well publicized, the limitations of available transthoracic, transepicardial, and true epicardial electrodes may be less appreciated,”³⁶ with 15% LV lead failure at 5 years.³⁷ In addition to lead failure, lead position, morbidity, and mortality must be considered. Utilizing pressure-volume loops, Dekker et al.³⁸ found epicardial sites that “did not significantly change left ventricular function and even worsened it in some cases.”³⁸ If surgical placement is attempted, the surgeon needs the same dedication as the implanting physician to place the LV lead in the appropriate location with good thresholds.

Although data are limited, without a prospective randomized comparison, complications and mortality appear to be much higher than the transvenous approach.^39–41 In the series by Ailawadi et al.,³⁹ the mortality was double, and postprocedural complications of acute renal injury (26.2% vs. 4.9%; P < .001) and infection (11.9% vs. 2.4%; P < .03) were more common in the surgical group. Based on analysis of the Replace Registry, surgical LV lead mortality may be greater than 8%; 48 patients (11% of 434 attempted LV lead placements) had a failed EP lab attempt. There were four deaths in the patients sent for surgical epicardial LV placement. Assuming every patient with a failed attempt went to surgery for an epicardial lead, the mortality is 8%.⁴⁰ However, we do not know how many of the 48 were actually sent for an epicardial lead, or if the patients who required surgical intervention were similar to those who did not.

Figure 22-4 is from a patient who underwent lead placement through an epicardial approach, showed no response, and then experienced improvement with a transvenously placed lead. Figure 22-5 contains the lateral chest radiographs of three patients who had failed transvenous implants, then did not respond to an epicardial lead, but improved when a lead was placed transvenously using guide-based delivery system and interventional techniques. If the patient is to be exposed to surgical risk, it is important to insist that the surgically placed leads are located on the midlateral free wall.

Figure 22-4 Epicardial versus transvenous lead placement for biventricular pacing.

A, The IS-1 connector end of the epicardial lead is shown in relation to the axillary vein. B, The epicardial screw-in lead and the occlusive coronary sinus (CS) venogram are shown. C, Anteroposterior view of the Attain 4194 lead (Medtronic) and the epicardial lead. D, Left anterior oblique view of the Attain 4194 and epicardial lead. The transvenous lead is in an ideal anatomic position on the midlateral wall according to the CS venogram. The epicardial lead is not in the ideal anatomic position.

Figure 22-5 Initial transvenous implant (CRT) “nonresponders.”

Three patients with initially failed implants who were epicardial LV nonresponders, but then had a successful transvenous implant and improved clinically. RV, Right ventricle.

 Left Ventricular Lead Position and Response

As mentioned earlier, not only does cardiac resynchronization therapy require pacing of the left ventricle, but the location of the lead can be important as well.^38,42 The midlateral wall of the left ventricle usually is the best location for an LV lead. When considering whether a patient is not responding to CRT, lead position can be important. The left anterior oblique (LAO) view on fluoroscopy at implantation should define the LV lead position. However, if the fluoroscopy is not performed in a standard manner, it can be deceptive. Kistler et al.⁴³ describe a case in which electrocardiographic analysis showed that a lead fluoroscopically thought to be in the left ventricle at implantation was actually in the right ventricle.

Another example of fluoroscopic error is shown in Figures 22-6 and 22-7. The LAO fluoroscopic image in Figure 22-6, A, appeared to document a lateral position. However, the lateral chest radiograph demonstrated the anterior location (Fig. 22-6, B). In Figure 22-7, A, the steeper LAO projection reveals the anterior nature of the first (“nonresponder”) LV lead position. It is important for the implanting physician to take personal responsibility for reviewing the final location of the LV lead, to ensure that the patient has received the best possible lead position. In follow-up of patients after implantation, we demonstrated that the left ventricular (LV)–right ventricular (RV) lead separation on the lateral chest radiograph is essential in evaluating “nonresponders” in whom LV lead placement has been “successful.”⁴⁴ Heist et al.⁴⁵ demonstrated that the acute hemodynamic effect of CRT is predicted by the LV-RV interlead distance, as measured on the lateral chest radiograph after the procedure. Placement of the LV lead on the anterior surface of the left ventricle is at best suboptimal, resulting in deteriorating LV function in some patients regardless of the method of implantation.³⁸ Unless convincing, specific information to the contrary is available, the midlateral free wall of \the left ventricle appears to be the optimal position for the LV lead. When the LV lead is on the midlateral wall, its position on a lateral chest radiograph is directly posterior. Figure 22-8 shows the typical postimplantation chest radiographs of a “responder” in whom the LV lead is located on the midlateral wall of the left ventricle. Note that the LV and RV leads are maximally separated on the lateral chest radiograph.

Figure 22-6 Fluoroscopy and chest radiography at initial implantation of left ventricular (LV) lead.

A, Left anterior oblique (LAO) fluoroscopic view shows the LV lead in what appears to be a lateral position, next to the epicardial screw-in leads from a prior implantable cardioverter-defibrillator (ICD). B, Lateral chest radiograph shows that the nonresponder LV lead position is actually anterior; black arrow indicates the separation between right ventricular (RV) and LV leads.

Figure 22-7 Fluoroscopy and chest radiography at second implantation.

A, Steep left anterior oblique (LAO) fluoroscopic view reveals the original Nonresponder left ventricular (LV) lead position (labeled LV lead position) to be anterior. The new responder LV lead position (labeled LV lead position) is midlateral. B, Lateral chest radiograph taken after the second LV lead was implanted confirms the posterior lateral lead position.

Figure 22-8 Chest radiographs of patient showing response to cardiac resynchronization therapy (CRT).

A, Anteroposterior (AP) view; B, lateral view. Arrow indicates the tip of the Attain 2187 left ventricular (LV) pacing lead (Medtronic, Minneapolis). The LV lead in B is located directly posterior the maximal distance from the right ventricular lead. This is the lateral chest radiograph of an LV lead on the midlateral wall.

Figure 22-9 includes the lateral chest radiographs of two patients who showed no response to CRT with their original lead position but did respond when a lead was positioned on the midlateral free wall. Figure 22-9, A, is the lateral chest radiograph of a nonresponder in whom the lead was placed in the anterior interventricular vein; patients with a lead in this location are not expected to show response. Figure 22-9, C, however, is the lateral chest radiograph of a patient who showed no response even though the LV lead had been placed in the vein to the midlateral free wall. What happened? The LV lead is advanced distally in the midlateral vein, which wraps around anteriorly toward the septum. Although the lead started in the vein to the midlateral free wall, it ended up anterior, close to the RV lead. Note that in Figure 22-9, A and C, the tip of the LV pacing lead is closer to the RV pacing lead than the ideal position seen in Figure 22-8, B. When a second LV lead was placed, this time on the lateral wall (Fig. 22-9, B and D), the patients improved clinically and were regarded as “responders.”

Figure 22-9 Chest radiographs of CRT nonresponders versus responders.

A, Anterior left ventricular (LV) lead is in the anterior vein. B, New lead is placed in a lateral vein, converting a CRT nonresponder to a responder. C, The lead starts in the lateral wall target vein but is advanced distally, which places the tip anterior (not apical) well beyond the ideal location. In both A and C, the physical separation between the right ventricular (RV) and LV leads (white arrows) is small. In both patients, new leads were placed (B and D) in positions similar to those shown in Figure 22-8, with marked improvement in symptoms. In the patient in C and D the new LV lead was placed more proximal in the same vein.

The clinical question raised is whether repositioning the LV lead of the patient in Figure 22-9, C, to a more proximal position in the same vein, thus increasing the RV-LV separation, would change a nonresponder to a responder. Figure 22-10 illustrates the original and new, more proximal positions in the same vein of a patient in whom such repositioning was performed. The RV-LV lead separation was increased, and the patient demonstrated a marked symptomatic improvement, objectified by reductions in both serum creatinine level and dose of diuretics.

Figure 22-10 Lateral chest radiographs before and after repositioning.

A, Left ventricular (LV) lead is anterior near the right ventricular (RV) lead. There is minimal RV-LV lead separation (black arrow). B, The LV lead is lateral; RV-LV lead separation (black arrow) is larger. Although the LV lead was placed in a midlateral wall vein, it was advanced distally, resulting in a more anterior position and lack of symptom response. When the lead was withdrawn more proximally in the same vein, the RV-LV lead separation increased, and the patient’s symptoms improved.

Figure 22-11, A, is the lateral chest radiograph of a patient in whom the original implanting physician was not prepared to perform coronary vein venoplasty. The vein to the midlateral wall was distal to a stenosis in the main body of the CS. Although the implantation was regarded as “successful,” the pacing lead was not placed on the midlateral wall of the left ventricle. The patient did not improve after the procedure, was regarded as a CRT “nonresponder,” and listed for heart transplantation. He was evaluated at our facility, where the lead position on the lateral chest radiograph was discovered. He subsequently underwent venoplasty of the main body of the CS, and the lead was placed on the lateral wall of the left ventricle (Fig. 22-11, B); dramatic resolution of symptoms eliminated the need for a heart transplant. Both the acute hemodynamic effect and the subsequent clinical response to CRT are predicted by the RV-LV lead separation on the lateral chest radiograph. On the basis of the work of Heist et al.,⁴⁵ the RV-LV separation in the horizontal plane is more important than the total RV-LV separation, and the RV-LV separation in the vertical plane was not predictive.

Figure 22-11 Chest radiographs of nonresponder before and after coronary sinus (CS) venoplasty and lead repositioning.

A, Lateral chest radiograph shows that left ventricular (LV) lead is anterior, near the right ventricular (RV) lead. Because of a stenosis in the main CS, the LV lead was placed in a posterolateral vein. To ensure stability and low pacing thresholds, it is advanced distally. There is minimal RV-LV lead separation. B, Venoplasty of the main CS was performed to provide access to the vein to the LV midlateral wall. The LV lead is directly posterior on the lateral chest radiograph. The RV-LV lead separation is greatly increased. With venoplasty of main CS and placement of LV lead on lateral wall, the clinical response was dramatic, and the patient’s name was removed from the heart transplant list.

 Guide Support–Based Delivery System

Since 1997, LV pacing leads have evolved from unipolar 6F stylet-driven to quadripolar 5F over-the-wire leads. Despite improvements in LV pacing leads, their placement continues to be limited by the coronary venous anatomy. Frequently, guide support is required because the angioplasty wire does not provide adequate support to advance the LV lead into the vein (Fig. 22-12). Guide support is present when the tip of the guide rests securely within the target vein and the back of the guide is supported by the coronary sinus, as occurs with a catheter where the tip is preshaped specifically to cannulate the target vein, not the CS. The magnitude of support provided by the preshaped guide depends on its shape, as shown in Figure 22-13; the compound shape in B offers greater support than the single curve in A because the secondary curve is supported by the CS back wall.

Figure 22-12 Despite wire placement, pacing lead does not track into target vein.

A, Wire is advanced into the target vein. B, Angioplasty wire does not provide adequate support for the acute angle; wire and lead pull out of the vein.

Figure 22-13 Shape of delivery guide determines magnitude of support.

A, The back of the delivery guide has a single curve and is not supported by the coronary sinus (CS). B, Delivery guide has a compound shape, such that the back of the guide is supported by the CS, and is expected to provide more support for the lead than that in A.

For the purposes of this chapter, a delivery guide is defined as a braided, slittable catheter preshaped for LV lead delivery (not for CS access) that is inserted through a separate catheter in the CS. A CS access catheter is defined as a removable catheter designed specifically for CS cannulation and to provide a platform for LV lead delivery. CS access catheters can occasionally provide guide support when it inadvertently cannulates the target vein or is forced into the vein. Forcing a CS access catheter requires an angle of less than 30 degrees, a situation where guide support is usually not required. Furthermore, the potential exists for dissection as the straight tip of the CS access catheter is forced around the curve (Fig. 22-14).

Figure 22-14 Perforation of vein by coronary sinus (CS) access catheter.

A, Limitations of attempting to advance the CS access catheter into the target vein. The wire and vein selector are in the target vein. Attempts to bend the straight tip of the CS access catheter into the target vein are not successful; the tip digs into the vein, causing a perforation. B, Radiographic example of the diagram. A contrast stain can be seen at the tip of the CS access catheter where it would not “turn the corner” into the target vein.

A delivery guide is the most reliable way to deliver a lead to the target vein, particularly when the anatomy is difficult (Fig. 22-15), but also even when the anatomy seems favorable (Fig. 22-16). In addition, the delivery guide makes it easier to deal effectively with lead instability, high thresholds, and phrenic pacing; inject contrast to identify branches; provide support to reposition the lead; or change to a lead of different size or shape and to a different method of fixation. Lastly, because the delivery guide allows the stylet to be safely advanced to the tip (Fig. 22-17), the final step of removing catheters from the CS is less likely to displace the lead. Accordingly, the approach to LV lead implantation described in this chapter is based on using a guide support–based delivery system.

Figure 22-15 Use of delivery guide.

Renal-shaped lateral vein introducer (LVI) for lead placement in a stenotic, acutely angled vein (SafeSheath Worley, Telescopic Series, Pressure Products). A, Occlusive coronary sinus (CS) venogram identifies the midlateral wall target vein with an acute angle and a stenosis near the os. B, Delivery guide is advanced without venoplasty into the target vein. The lumen of the guide and vein are coaxial. The pacing lead (Attain 4194, Medtronic) advances into the vein.

Figure 22-16 Delivery guide required for lead placement.

A, Target vein is large, and it appears that LV lead placement will be easily accomplished. B, Attempts to advance the 6-French (6F) LV lead (Attain 4194, Medtronic) from the straight 7F ID coronary sinus (CS) access catheter (Attain Access 6218) is unsuccessful. C, Attempts to advance the 5F lead (Attain 4193, medtronic is also unsuccessful. D, CS access catheter is upsized to 9F ID (Worley-STD, Pressure Products) and the 7F ID delivery guide (Worley Renal LVI) is advanced into the target vein. With the delivery guide in place the 6F LV lead is advanced.

Figure 22-17 Reducing risk of lead dislodgment as catheters removed.

A, Delivery guide is in place, and the stylet is advanced to the tip of the lead. B, Delivery guide is removed without displacing the lead.

The guide support–based delivery system comprises four separate components, allowing optimized design of each component for its particular function. Although an LV lead can be delivered with a single- or two-component system, use of the following four components provides the best opportunity for success in the least amount of time with the shortest learning curve:

Figure 22-18 Telescoping cannulation assist for coronary sinus (CS) access catheters.

The CPS AIM cannulator is telescoped within the CPS Direct outer guide (St. Jude Medical). The braided core is telescoped within the SafeSheath CSG Worley (Pressure Products). The CPS Direct and CSG Worley are CS access catheters. The CPS Aim and Braided Core are telescoping cannulation assist catheters. Manipulation of the telescoping assist catheter within the CS access catheter facilitates location and cannulation of the CS. The SafeSheath CSG Worley (CSG/Worley/BCore-1-09) includes the Braided Core, which also serves as a temporary metal braid to provide torque control for the peel-away sheath (CS access catheter).

Shape and Use of Delivery Guides

Previous Approach

In the third edition of this book, I emphasized matching delivery guide shape to the target vein anatomy for two reasons. First, at that time we used either interventional guides from radiology or the first-generation Pressure Products delivery guide (Fig. 22-19, A). Both had very firm tip sections, which could not be advanced into the target vein or did not remain stable once advanced (Fig 22-20). However, with the new soft-tip design (Fig. 22-19, B), the Pressure Products delivery guide can be advanced deep into the target vein and remains stable.

Figure 22-19 Comparison of tip section of original and current delivery guides.

A, Tip of the original Pressure Products delivery guides was the same stiffness as the shaft, similar to the interventional guides that were used initially. The stiff tip section is difficult to advance deep into a vein and is not stable if advanced. B, In the current version of the delivery guide (Telescopic Braided Renal LVI/75-5-66-55-RE) the tip section is much softer than the shaft. Using the included vein selector, it can be advanced deep into a vein and remains stable; thus multiple shapes are no longer necessary.

(Courtesy Pressure Products, San Pedro, Calif.)

Figure 22-20 Stiff tip prevents secure advancement of interventional and delivery guides into target vein.

The tortuous vein segment is shown in anteroposterior (A) and left anterior oblique (B) views. C, The older-model Pressure Products 7-French (7F) ID renal delivery guide is advanced through the 9F ID CS access catheter to the ostium of the target vein over a 5F vein selector (Williams Right Diagnostic, Boston Scientific, Miami) and an angioplasty wire. D, Renal delivery guide is advanced over the 5F vein selector beyond the tortuous segment. E, When the vein selector is removed, the stiff tip of the older-model delivery guide retracts proximal to the tortuous vein segment. The soft tip of the current-model renal delivery guide (Telescopic Braided Renal LVI/75-5-66-55-RE, Pressure Products) can be advanced deep into the vein over a vein selector and remains stable once in place.

Second, it initially appeared that the delivery guide could be used reliably to locate the vein, advance the wire, and then be advanced over the wire into the vein. Although effective in some cases, we found that the delivery guides were not optimal for small or off-axis target veins, necessitating the addition of a small, diagnostic catheter telescoped through the delivery guide (see Fig. 22-1). It thus became clear that a small diagnostic catheter (vein selector) was an essential component of a guide support–based delivery system and needed to be included with the delivery guide (see Fig. 22-3).

New Approach

Recognizing that a vein selector will be needed to locate and cannulate the target vein in at least some cases, and that the soft tip of the new Pressure Products delivery guide can be advanced to a stable position deep in the vein if needed, we now rely on the shape of the vein selector for off-axis and difficult veins and use a single shape of delivery guide. Using the included vein selector and wire(s) as a rail the “renal” delivery guides can be inserted into the vast majority of target veins, regardless of takeoff (Fig. 22-21). We rarely if ever use one of the other shapes of Pressure Products delivery guides (hook, hockey stick, or multipurpose). The vein selectors also work in the same manner with the device company delivery guides.

Figure 22-21 Renal-shaped delivery guides with vein selector.

A, The 7-French (7F) “renal” delivery guide is shown with the included 5F standard vein selector (Telescopic Braided Renal LVI 75-5-66-55-RE, Pressure Products). It has a 7F outer diameter (OD), 5.5F inner diameter (ID), and a working length of 66 cm. B, The 9F OD renal delivery guide is shown with the included 5F standard (std) vein selector (Telescopic Braided Renal LVI 75-5-62-07-RE). It has a 9F OD, 7F ID, and working length of 63 cm. The soft tip section of the delivery guide can be advanced deep into a target vein over the vein selector, if needed. As a result, we now rely on the shape of the vein selector, not the shape of the delivery guide, to accommodate the takeoffs of various veins. When used with a vein selector, the renal-shaped delivery guide is suitable for the vast majority of cases. In approximately 10% of cases, one of the other two vein selectors (Impress CS Vert p/n 1628-017 or Impress CS Hook p/n 1628-019, Merit Medical; see Fig. 22-3) may be required to locate and cannulate the target vein.

 Left Ventricular Lead Implantation with Interventional Techniques

Details and Rationale

This section describes my recommendations for implanting LV leads and the tools used. Chapter 23 describes more advanced interventional technique, including crossing total occlusions, subclavian and coronary vein venoplasty, using balloons as anchors, and use of snares. With these techniques, we have successfully implanted all 27 patients with failed implants referred from other centers, including five who had epicardial leads but did not respond.

When a biventricular (BiV) implantation is begun, there is no way to predict what lies ahead. For example, it may be difficult to find the vein; the subclavian vein may be stenotic or occluded; the CS os may be difficult to locate; and the main CS may be tortuous. The CS venogram may reveal a range of target veins, from easy to extremely difficult. Once the lead is in the target vein, the implanter must be prepared to deal with phrenic pacing or high pacing thresholds. Once the lead is in a satisfactory location, the implanter must anticipate and prevent the lead from being displaced either spontaneously or as the final catheter or stylet is removed. A CRT implantation ultimately fails as a result of patient anatomy for which the implanter is not prepared. In effect, the implanting physician and the patient are “victimized” by the patient’s anatomy. To succeed, the implanter must be prepared to deal with whatever anatomy is encountered, starting with venous access and ending with the final removal of the stylet.

Prepare Patient for Iodinated Contrast Material

The safe use of contrast is discussed in detail in Chapter 23. In summary, contrast improves safety, reduces implant time, and is essential to the use of a guide support–based delivery system. Rather than only trying to limit contrast, it is better to take steps to prevent nephropathy. Use of contrast can then be individualized; many patients will be at relatively low risk, whereas others (e.g., diabetics with increased creatinine) remain at high risk. Because the serum creatinine can vary substantially in CRT patients depending on volume status, we recommend hydration for all patients as follows:

Normal saline or sodium bicarbonate, 3 mL/kg/hr for 1 hour starting 1 hour before the procedure and continuing 6 hours after the procedure. This hydration protocol is as effective as giving 1 mL/kg/hr of normal saline 12 hours before, during, and for 12 hours after the procedure, and the patient receives less volume. Although volume overload is possible, it is rare and offset by the advantage of preventing nephropathy.

Equipment and Room Setup

Four of the most important and most easily overlooked parts of LV lead implantation are mechanical issues that can be easily resolved before the procedure starts. Careful attention to these issues and actions to avoid them can make the difference between an agonizing unsuccessful attempt and a 15-minute LV lead placement.

Collect Available LV Lead Implantation Equipment and Review Its Use

The worst mistake may be to assume that the equipment required for a successful efficient LV lead implantation either is in the room or has been provided by the manufacturer. Some of the equipment is readily available in the hospital but is not part of the usual repertoire of many implanting physicians. Knowledge of the equipment used in interventional radiology and interventional cardiology can be extremely useful during an LV lead implantation (see Interventional Implant Equipment List at end of chapter). The technical staff and physicians from interventional cardiology and radiology often have helpful suggestions for solving the mechanical problems posed by an LV lead implantation, and equipment specifically tailored to LV lead placement is slowly making its way into the world of electrophysiology. Access to these new tools can make the difference between an easy success and a painful, demoralizing failure.

Organize Equipment to be Readily Available in Room

It is important to remember that the interventional implant equipment needed is not usually available in a room used for either pacer implantation or an EP study. To avoid spending more time surveying the interventional cardiology and radiology laboratories than actually working on the patient, the physician should make certain of having the most basic equipment in the room. These tools are additional to the device company equipment and sheaths used for pacemaker implantation. To be certain we have the proper tools regardless of the room, our staff created a “BiV Cart.” This cart also contains equipment for performing subclavian and coronary vein venoplasty (Fig. 22-22).

Figure 22-22 Biventricular (BiV) cart.

A, Front view; B, back view. Cart keeps equipment readily available in any implantation room when needed.

Assemble “Always Used” Equipment on Table before Starting

Having a routine and setting the table with equipment needed for the procedure give the operator the freedom to concentrate on the procedure and help avoid “rethinking” the tools for each implantation (Fig. 22-23).

Figure 22-23 Simplified system to allow assistant to inject contrast while operator manipulates catheter with both hands.

For right-handed operator, the right hand is on the rotating hub on the Y adapter, and the left hand is on the catheter. The system is used to inject contrast for location of the coronary sinus os, for the occlusive venogram, and for locating the target vein with the vein selector. The system can be constructed from equipment readily available in most laboratories and is available as a kit (Pressure Products or Merit Medical; see equipment list at end of chapter for details). The scrub technician should have the pieces on the table and assembled before notifying the implanting physician to scrub for surgery.

Pay Careful Attention to Orientation of Instrument Table During Procedural Stages

It is remarkable how important the position of the instrument table can be to a successful implantation. It is even more remarkable how frequently even an experienced implanter forgets to change to a table position appropriate to the stage of the procedure until either the support staff provides a gentle reminder or something that should be easy feels difficult. Figure 22-24, A, demonstrates the usual “backfield” position of the instrument table. We keep the table in this position until we start CS access, at which point the table is turned perpendicular to the patient (Fig. 22-24, B). Once the LV lead is in place and it is time to start removing the guide and sheath, the table is returned to the backfield position so the assistant can support the sheath and lead during sheath and guide removal.

Figure 22-24 Instrument table position during LV lead implantation.

A, Instrument table in traditional “backfield” position; the acute angle of the catheters results in loss of torque control, tendency for catheters to kink, and catheters prone to fall off the table. The table position is ideal for working with the right ventricular (RV) and right atrial (RA) leads, retraction for pocket formation, and trimming suture. B, Instrument table is perpendicular to patient. As soon as the operator begins to obtain venous access for the left ventricular (LV) pacing lead, the instrument table is moved into a position perpendicular to the patient. The long wires, sheaths, and guides may thus be kept straight as they exit the body. The assistant works at the table beside the operator to assist with contrast injection; control the long guidewires, sheaths, and torque devices; and insert the pacing lead onto the wire as the procedure progresses. Ideally, the table would be at the same height as the patient’s chest. Some centers use a Mayo stand for this purpose, but my colleagues and I value the additional table length over the ideal height. However, the perpendicular table position blocks the assistant’s access to the field. The table must be returned to the standard backfield position to slice the guide and to peel the sheath.

The perpendicular position of the table from the start of CS cannulation until removal of the guide or sheath can be cumbersome with standard tables, for the following reasons:

• The legs of the table closer to the patient interfere with the position of the operator’s feet and the fluoroscopy pedals.

• The legs of the table interfere with rotation of the fluoroscopy unit, particularly in the right anterior oblique (RAO) position.

• The height of the standard instrument table is lower than the height of the patient. As a result, wires and catheters do not make a smooth transition from the patient to the table.

The custom-built table shown in Figure 22-25 addresses all three issues. The legs are recessed to provide room for the fluoroscopy unit, the operator’s feet, and fluoroscopy pedals. The height is adjustable so that the top of the table can be raised to reduce the vertical stepoff between the patient and the table. Interventional principles teach that when working with catheter, it is important that the implant table be turned perpendicular to the patient table (T-bone position) so that the wires and catheters exit the body falling naturally onto the table (see Fig. 22-24, B). Further, the assistant is in the optimal position to assist with the catheter manipulation, contrast injection, and wire exchanges required for LV lead implantation and the use of balloons. Application of torque to the catheters is not lost in a right angle, and the open-lumen catheters are not prone to kink. Testing the left and right ventricles simultaneously for pacing thresholds can be difficult with standard testing cables. Simply attaching an additional alligator clip eliminates this problem (Fig. 22-26).

Figure 22-25 Custom-made table to facilitate LV lead implantation.

A, Side view of custom-designed biventricular (BiV) implantation table. The importance my colleagues and I place on the perpendicular position of the table is exemplified by the time and energy we devoted to optimizing the table for the LV lead implantation phase of the procedure; we (1) moved the supporting legs of the table back 18 inches (45 cm) from one end and (2) added height adjustment to the table. When placed perpendicular to the patient, the legs of a standard table interfere with the position of the foot pedal for fluoroscopy as well as the operator’s feet. In addition, the legs interfere with the table position when the radiograph tube is rotated for a right anterior oblique projection. Moving the supporting legs of the table back 18 inches from one end allows the table edge to approximate the patient without interfering with either radiography or the operator’s feet. The height of the table is adjustable to ensure a smooth transition of catheters and wires from the patient to the table while the operator is working perpendicular to the patient (BiV position). B, Skew view of the same table (Oscor, Palm Harbor, Fla).

Figure 22-26 Biventricular pacing cables.

When determining LV and right ventricular (RV) pacing thresholds to a single cathode, it is time-consuming and tedious to attach both anodes of the pacing leads to a single alligator clip. Simply having a second anode alligator clip greatly facilitates this phase of the procedure.

Approach to Contrast

An important point frequently overlooked is the approach to contrast injection. EP physicians accustomed to working alone with solid catheters naturally try to inject contrast and control the catheter. However, interventional principles clearly show that catheter control is degraded when one hand is removed from the catheter and attention is turned to contrast injection. Suboptimal catheter control will result in increased use of contrast and a greater chance of misadventure. For optimal catheter control, the operator keeps both hands on the catheter and attention focused on tip position (Fig. 22-27).

Figure 22-27 Contrast injection by operator and assistant.

A, Operator attempts to inject contrast and manipulate the catheter simultaneously. Interventional principles teach that both hands need to be on the catheter for good control, one on the hub and the other on the shaft where it enters the sheath. In addition, when contrast is injected, focus is diverted from the position of the catheter tip to the injection syringe. B, Simplified injection system is connected to the catheter by a rotating-hub Y adapter. Extension tubing is connected to the Y adapter and a three-way stopcock with reservoir syringe and injection syringe. The assistant has room to stand next to the operator and inject contrast when requested. The operator can keep both hands on the body of the catheter and keep attention focused on the tip of the catheter.

Venous Access

At first, venous access may seem like a minor issue, but keep in mind the cascade of events that follows a difficult venous access. If compression between the clavicle and first rib, friction between the leads, or subclavian stenosis restricts manipulation of the leads or sheath, the operator is handicapped for every subsequent step. The operator will not be prepared for difficult anatomy in subsequent steps if the result of the first step limits options. A poorly considered initial venous access will be problematic throughout the procedure.

Preventing Restricted Catheter/Lead Movement

Separate Access for Each Lead

Having separate access sites for each lead reduces the interaction among the three leads. If only two access sites can be obtained, the RV and RA leads should be placed through the same access site to minimize the potential for movement of either lead to displace the LV lead. When leads share the same access, friction between the two may result in the stable lead being withdrawn by manipulation of the other lead. To help prevent lead withdrawal, keep the stylet of the stable lead at the junction between the inferior vena cava (IVC) and superior vena cava (SVC) until manipulation of both leads is complete, even after the stable lead is tied down. Without a stylet, the stable lead can withdraw, even when tied to the muscle, by forming an S configuration within the subclavian vein distal to the tie-down (Fig. 22-28).

Figure 22-28 Friction between lead and guide pulls back lead, even though sewn down.

A, Atrial lead is in place and secured to the muscle. B,

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