Echocardiographic Assessment of Patients with Systolic Heart Failure

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2 Echocardiographic Assessment of Patients with Systolic Heart Failure

Sorin Pislaru, Maurice Enriquez-Sarano

Definition, Staging, and Etiology of Systolic Heart Failure

• Heart failure (HF): abnormality of cardiac function responsible for inability of the heart to provide blood flow at rates commensurate with tissue requirement, or to do so only at increased filling pressures.

• HF stages ¹

Stage A: risk factors for HF, but normal ventricular function, no symptoms

Stage B: ventricular dysfunction (systolic/diastolic), but no symptoms

Stage C: ventricular dysfunction and mild symptoms

Stage D: ventricular dysfunction and severe symptoms

• Systolic heart failure

• Implies impairment of systolic ventricular function.

• It is a common end stage for a variety of cardiac diseases.

• It can be left ventricular, right ventricular, or biventricular.

• The single most useful diagnostic test in the evaluation of patients with HF is the comprehensive two-dimensional (2D) echocardiogram coupled with Doppler flow studies.¹ The goals of echocardiography in systolic HF are:

• Define etiology and in particular determine if systolic HF is due to a primary myocardial disease (including consequences of coronary disease) or a primary valve disease.

• Define the degree of systolic ventricular dysfunction and remodeling (Table 2-1).

• Define the degree of diastolic ventricular dysfunction (addressed in Chapter 3).

• Define the presence and severity of functional mitral regurgitation (MR) and/or tricuspid regurgitation.

• Define the hemodynamic consequences (cardiac output, pulmonary and atrial pressures).

TABLE 2-1 LEFT VENTRICULAR QUANTIFICATION METHODS: USE, ADVANTAGES, AND LIMITATIONS

Dimension/Volumes	Use/Advantages	Limitations
Linear
M-mode	Reproducible	Beam frequently off-axis
M-mode	High frame rates	Single dimension not representative in distorted ventricles
2D-guided	Assures orientation perpendicular to LV axis	Lower frame rates than in M-mode
2D-guided		Single dimension only
Volumetric
Biplane Simpson’s method	Corrects for shape distortions	Apex frequently foreshortened
	Minimizes mathematic assumptions	Endocardial dropout
		Relies on only two planes
Area-length method	Partial correction for shape distortion	Based on mathematic assumptions
3D echocardiography	Best correlation with MRI	Endocardial definition
3D echocardiography	Further enhanced by contrast use

Echocardiographic Methods for Assessment of Left Ventricular Systolic Function

Image Acquisition and Interpretation

• Various imaging modalities can be used for assessment of left ventricular systolic function (see Table 2-1).

• Classical indexes of left ventricular function are derived from linear and volumetric data.³

• Image optimization is a key step in obtaining accurate measurements. Always adjust focus depth, sector size, and lateral gains to optimize axial and temporal resolution.

• Harmonic imaging increases wall thickness and decreases internal dimensions slightly.

• Color B-mode maps and/or intravenous contrast may be needed for wall motion analysis.

• Assessment by Doppler echocardiography is always comprehensive, integrating all methods available (e.g., ejection fraction [EF] is judged visually and compounded with calculated EF from M-mode or 2D diameters or LV volumes).

Indexes of Global Left Ventricular Systolic Function

• Left ventricular size

• LV size is measured by the diameter at the mitral leaflet tips; calculation is simple but not linearly related to LV volumes.

• Left ventricular volumes can be calculated from 2D imaging (area-length or method of disks) and from three-dimensional (3D) imaging with specific software. End-systolic volume index is an important index of LV remodeling and function.

• EF by visual assessment

• This value is an estimation based on appreciation of ventricular area change in systole from multiple views.

• Calculation is simple but underestimates EF in the very low range (an area change of 10% equals an EF of 19%).

• It serves as a background check for calculation methods.

• EF by linear measurements (Figure 2-1)

• Calculation is based on the LV internal diameter at end-diastole and end-systole.

• Electrocardiography (ECG) serves only as a guidance; valve and wall motion should also be considered in selecting end-diastolic and end-systolic frames.³

• EF calculations are based on Teichholz or Quiñones methods.

• Linear measurements (M-mode, 2D) have several disadvantages (see Table 2-1).

• EF by volumetric measurements (Figure 2-2)

• Calculation does not have geometric assumptions.

• LV apical foreshortening and lateral resolution on 2D images can be significant limitations (see Table 2-1).

• 3D contrast-enhanced echocardiography has the best correlation with magnetic resonance imaging (MRI) in terms of assessment of LV and RV volumes.

• Stroke volume and cardiac output (Figure 2-3)

• These values are based on 2D (LV outflow tract [LVOT] dimension and calculated area) and Doppler (blood velocity) measurements, with calculation of stroke volume as the product of LVOT area by time-velocity integral (TVI).

• LVOT diameter measurement can be underestimated, and small errors in LVOT measurements are squared in area calculation. Careful zoomed imaging with decreased gain, and learning curve with calculation of cardiac index, are essential in accuracy.

• Other parameters used in assessment of global LV systolic function

• Mitral annular systolic velocity (tissue Doppler imaging [TDI])

• Global left ventricular peak systolic strain (Figure 2-4)

• Estimated left ventricular dP/dt (Figure 2-5)

• LV mass is measurable using wall thickness and LV size and is particularly important in hypertensive patients. LV mass is always increased with LV dilatation, but prognosis is more based on quality than on quantity of muscle.

Figure 2-1 Left, M-mode measurement of left ventricular end-diastolic (LVEDD) and end-systolic (LVESD) dimensions. EF can be then calculated based on Teichholz or Quiñones formulas. Right, Note that only the M-mode obtained along the center line is perpendicular to the LV long axis. M-mode images obtained on the outer lines would overestimate left ventricular size, a common problem in M-mode measurements.

Figure 2-2 EF measurement based on the method of disks. End-systolic and end-diastolic frames are used to trace the endocardial border on standard apical 4-chamber (top panel, left ventricle on the left side) and 2-chamber (bottom panel ) views.

Figure 2-3 Stroke volume (SV) calculations are based on measurement of LVOT diameter and LVOT TVI. The LVOT is assumed to be circular and the area is calculated by the formula: A = π × d²/4 = 0.785 × d². The cardiac output is then calculated by multiplying the SV and the heart rate at the time of acquisition.

Figure 2-4 Measurement of left ventricular peak longitudinal systolic strain in a patient with hypertrophic cardiomyopathy. The software automatically tracks the area of interest and calculates left ventricular strain based on speckle tracking (left panel—example of tracking in 4-chamber view). The average peak negative systolic strain can be then calculated from measurements performed on each of the 17 segments, and can be displayed as a bull’s-eye diagram (right panel); this can also serve for assessment of regional left ventricular function. The peak negative longitudinal systolic strain has gained importance in assessment of early changes in systolic function in patients with infiltrative and hypertrophic cardiomyopathies.

Figure 2-5 Measurement of left ventricular systolic dP/dt is based on the mitral regurgitant signal. Since in the very early phase of systole the MR does not significantly increase the atrial pressure, it can be assumed that the increase in MR regurgitant velocity directly reflects changes in intraventricular pressure. By measuring the time needed for the MR velocity to increase from 1 to 3 m/s, dP/dt can be calculated according to the formula: dP/dt = (4 × 3² − 4 × 1²)/time = 32/time.

Assessment of Regional Left Ventricular Function

• Assessment of regional wall motion abnormalities (RWMAs)

• The American Society of Electrocardiography (ASE) recommends a 17-segment LV model (Figure 2-6).

• Motion of each segment is evaluated on a semiquantitative scale (1 = normal or hyperkinesis; 2 = hypokinesis; 3 = akinesis or negligible thickening; 4 = dyskinesis/paradoxical systolic motion; 5 = aneurysmal).

• RWMA due to ischemia does not occur at rest until epicardial coronary artery stenosis is greater than 85%.

• Echocardiography overestimates the area of ischemic or infarcted myocardium as adjacent regions are affected by tethering, regional loading conditions, and stunning.

• The presence of regional left ventricular dysfunction not respecting coronary distribution can be seen in various diseases, such as post–coronary artery bypass grafting, infiltrative cardiomyopathies (sarcoidosis), cardiac tumors, myocarditis, etc.

• Other tools are gaining momentum in assessing regional wall motion, particularly segmental left ventricular strain or strain rate (see Figure 2-4).

Figure 2-6 The 17-segment model used for assessment of left ventricular regional wall motion. Top panel: Short-axis schematic with six basal and midventricular segments and four apical segments. Bottom panel: Corresponding long-axis parasternal and apical 4-chamber and 2-chamber views. The 17-segment model adds an apical cap segment.

Assessment of LV Diastolic Function

• LV relaxation is always slowed when systolic function is reduced.

• Diastolic dysfunction analysis is based on the combination of mitral and pulmonary venous flows and TDI.

• Simple relaxation abnormality (stage I) is benign, while restrictive filling (stage III/IV) indicates elevated filling pressures.

Assessment of Functional Regurgitation (Mitral, Tricuspid)

• Assess structural normalcy of valves.

• Estimate or, better, quantify regurgitation.

Echocardiographic Assessment of Specific Causes of Systolic Heart Failure

Ischemic LV Dysfunction

• Ischemic LV dysfunction is the most common cause of systolic HF.

• The presence of resting RWMAs in a coronary artery distribution pattern and/or evidence of old myocardial infarction (thinned, scarred myocardial wall; LV aneurysm) are key echocardiographic findings.

• Resting RWMAs can also be seen with stunned/hibernating myocardium and occasionally in non-ischemic disease.

• Intravenous contrast should be used whenever endocardial border definition is suboptimal in two or more contiguous segments.

• Stress echocardiography is an established method of assessment of myocardial ischemia.

• Exercise (treadmill or stationary bike) is the preferred stress method. It can be combined with oxygen consumption for better quantification of exercise ability. Dobutamine is the most commonly used pharmacologic stress agent.

• Interpretation is based on regional wall motion analysis and global response to stress (change in left ventricular dimension and EF with stress).

• With stress, RWMAs can occur with epicardial coronary stenoses as low as 50%.

• A biphasic response to dobutamine in at least two segments with resting RWMAs (improvement at low dose followed by worsening at high dose) is suggestive of viable myocardium and epicardial coronary artery disease (hibernating myocardium).

• MR can be associated with ischemic left ventricular dysfunction, and is most commonly due to tethering of the posterior mitral leaflet (Figure 2-7); an effective regurgitant orifice (ERO) greater than 0.20 cm² and a regurgitant volume greater than 30 mL are associated with poor prognosis.

• Always assess for intraventricular thrombus in patients with low EF and aneurysmal changes (Figure 2-8). This is best done by administration of intravenous contrast.

Figure 2-7 Typical appearance of ischemic MR in a patient with severe left ventricular dysfunction. Note extreme LV dilatation with thinned inferolateral wall (top left) and restrictive filling pattern on the mitral inflow (top right). Both mitral leaflets are tethered in systole, the posterior leaflet more than the anterior (bottom left). This results in incomplete coaptation and override of the anterior leaflet, with a posteriorly directed jet of MR (bottom right).

Figure 2-8 Intravenous contrast for assessment of intracardiac thrombus. Top row: Apical infarct with aneurysm formation in a patient with history of apical cardiomyopathy. Left panel shows wall thinning and intracavitary haziness at the apex (arrow), suspicious for apical thrombus. This is effectively ruled out on the contrast image (right panel). Bottom row: Apical aneurysm formation after LAD infarction. Note the inconspicuous appearance on standard 2D echocardiography (left panel). Since the endocardial definition was suboptimal, intravenous contrast was administered. This clearly shows the presence of an apical thrombus (arrow) but also apical LV wall thinning consistent with an old infarction (right panel ).

Key Points

• RWMAs can be seen in a variety of conditions, but their most common cause is myocardial ischemia.

• The preferred stress modality is treadmill exercise.

• A biphasic response to dobutamine is suggestive of myocardial viability.

• Mitral regurgitation can be associated with ischemic left ventricular dysfunction.

• Intravenous contrast administration is helpful for accurate assessment of RWMAs and intracardiac thrombus.

Dilated Cardiomyopathy

• Idiopathic (~50%) and secondary dilated cardiomyopathies have similar echocardiographic findings.

• Diagnosis requires presence of an enlarged ventricle with reduced EF (<40%) or reduced fractional shortening (<25%).

• Generalized left ventricular hypokinesis is usually present, although some of the basal segments can be relatively spared.

• Valvular disease (functional MR and tricuspid regurgitation) is often present and may further worsen ventricular dysfunction.

• Treatment and prognosis vary depending on the etiology.

• Heart transplantation and/or left ventricular assist devices (LVAD) are frequently considered.

• Implanted continuous-flow LVADs have unique echocardiographic findings (Figure 2-9):

• Lack of (or minimal) systolic opening of the aortic valve

• Continuous aortic regurgitation (when present)

• Left ventricular apical inflow cannula is usually well seen

• Continuous flow in the ascending aorta

• The outflow cannula is more difficult to visualize by the transthoracic approach (high position in the ascending aorta). Right parasternal imaging can help.

• Critical echocardiographic evaluations in LVAD patients are:

• Assessment of valvular competency (especially aortic and tricuspid)

• Assessment of possible inflow/outflow cannula obstruction by color Doppler and continuous wave (CW)/pulsed wave (PW) Doppler

• Cardiac output can be estimated from careful assessment of the RV outflow tract (RVOT) diameter and RVOT TVI (similar to the left heart assessment).

Figure 2-9 Typical appearance of an LVAD (HeartMate II) implanted as destination therapy. Orthogonal plane imaging from midesophageal position showing normal position of the apical inflow cannula (top panels). The aortic valve remains closed during systole (note position of the ECG marker; bottom left). CW Doppler in the ascending aorta at the tip of the outflow cannula shows continuous flow (bottom right ).

Key Points

• Idiopathic and secondary causes of dilated cardiomyopathy have similar echocardiographic features.

• Functional valvular regurgitation is often present.

• LVAD assessment has unique echocardiographic features.

Left Ventricular Dysfunction Resulting from Valvular Disease

• Long-standing severe aortic valve disease (both stenosis and regurgitation) and MR are associated with left ventricular dysfunction.

• Isolated mitral stenosis is not associated with left ventricular systolic dysfunction.

• Echocardiography is the cornerstone of evaluating valvular disease.

• It establishes the etiology and responsible mechanism.

• It allows reproducible quantification of disease severity.

• Echocardiography-derived parameters have prognostic implications and are used in determining the need for surgical correction.

• Assessment of valvular disease severity is based on integrating data from several echocardiographic imaging modalities (Table 2-2).

• Formal volumetric quantification of valvular disease severity is based on the continuity-of-flow principle.

• Proximal isovelocity surface area (PISA) method (also based on continuity of flow) has become the preferred modality for evaluating regurgitant lesions (Figure 2-10).

TABLE 2-2 ECHOCARDIOGRAPHIC CLASSIFICATION OF THE SEVERITY OF VALVULAR DISEASE IN ADULTS

Figure 2-10 PISA quantification method is based on the flow convergence concept. Blood flow progressively accelerates as it approaches the regurgitant orifice, forming hemispheric surfaces of equal velocity (isovelocity surfaces). Identification of such a surface is facilitated by shifting the 0 velocity line in the direction of the regurgitant jet. In this way, the velocity range in the direction of flow is significantly reduced, with aliasing occurring at lower velocity (hence further away from the orifice and easier to measure). The radius r is measured from the aliasing front line (sudden color change on color Doppler) to the narrowest point of the regurgitant jet (regurgitant orifice). Assuming the flow through the isovelocity surface area is equal with the flow through the regurgitant orifice, one can calculate the ERO and regurgitant volume according to the formulas outlined in the figure. Right panels show an example of PISA estimation of the ERO and RV in a patient with severe mitral regurgitation.

Mitral Regurgitation

• MR is the most common valvular disease in the United States.⁴

• It is the result of the loss of normal systolic coaptation between the anterior and posterior leaflets.

• Echocardiography is uniquely positioned for comprehensive assessment of normal mitral valve anatomy (Figure 2-11).

• The anterior and posterior mitral leaflets are further subdivided into three scallops (A1 through A3, P1 through P3).

• The mitral annulus has a saddle shape as a result of which mitral valve prolapse is diagnosed based on the long-axis parasternal view (valve more than 2 mm below the annular plane).

• Estimating disease severity based on color Doppler imaging alone is fraught with errors.

• Severity can be overestimated as a result of low aliasing velocity limits on the color Doppler scale or of entraining left atrial stagnant blood by the high-velocity MR jet. These make the jet look worse than it actually is.

• Eccentric, wall-hugging jets dissipate energy by contact with the atrial wall (Coanda effect); their color Doppler appearance can be underwhelming.

• In patients with very high left atrial filling pressures, MR can be nearly silent Xon color Doppler alone (acute MR due to papillary rupture, functional ischemic MR).

• Left atrial volume reflects volume overload from MR and has prognostic value.

• Degenerative disease is the most common cause of MR in the western world (60% to 70% of cases).

• Surgical correction of MR is dependent on both cause and mechanism, which affect repairability. Therefore, comprehensive evaluation is of paramount importance in the decision for and planning of surgical intervention.

• Intraoperative real-time 3D transesophageal echocardiography (TEE) is particularly useful for assessment of the mitral valve.

• Echocardiography-derived indications for surgery in asymptomatic patients with severe MR:

• Class I: left ventricular dysfunction (EF < 60% or left ventricular end-systolic dimension > 40 mm)

• Class IIa: pulmonary artery pressure greater than 50 mm Hg at rest or 60 mm Hg with exercise ⁵

• Indications for serial echocardiographic evaluation:

• Every 6 to 12 months for patients with asymptomatic severe mitral regurgitation

• Whenever change in symptoms is suspected to be secondary to MR

• Contraindicated for routine follow-up of patients with mild MR

Figure 2-11 Schematic representation of the mitral valve scallops (top) and the typical appearance of flail posterior scallops on the TEE commissural view (bottom).

TABLE 2-3 CAUSES OF MITRAL REGURGITATION

Figure 2-12 TEE images obtained from a patient with severe organic MR due to a flail P2 scallop of the mitral valve (top, commissural view; middle, long-axis midesophageal view). Note the very eccentric, anteriorly directed jet of MR. Compare with the functional MR shown in Figure 2-7.

Key Points

• MR results from lack of mitral coaptation due to organic or functional mechanisms.

• Color Doppler can over/underestimate disease severity. It should never be used as a sole assessment of disease severity.

• Systematic assessment of MR should include establishing the cause and mechanism, formal quantification of disease severity, and assessment of associated pathology.

• Success of surgical repair depends on both the etiology and the mechanism of MR.

• Serial echocardiograms are recommended in patients with severe asymptomatic MR.

Aortic Stenosis

• Left ventricular systolic dysfunction is a late manifestation of severe aortic stenosis (AS).

• Systematic echocardiographic evaluation of patients with AS:

• Step 1: establish the location of the obstruction and native valve morphology.

• Valvular/subvalvular/supravalvular

• Tricuspid/unicuspid/bicuspid/quadricuspid (Figure 2-13)

• Step 2: evaluate severity of disease (see Table 2-2).

• Estimate aortic valve gradient by systematic CW Doppler interrogation (all available windows, use of non-imaging CW Doppler probe).

• Valve area calculation is based on continuity equation.

• LVOT measurement can be difficult due to acoustic shadowing from calcification, which is prone to induce errors. Always perform on zoomed-up view.

• Dimensionless indexes (aortic/LVOT TVI and velocity ratio) are helpful, especially when LVOT measurement is difficult.

• Calculation of valve area by planimetry is unreliable on transthoracic echocardiography; TEE measurements correlate with calculated valve area at hemodynamic catheterization.

• Step 3: evaluate for associated conditions.

• Enlargement of ascending aorta, coarctation

• Serial echocardiographic evaluation:

• Recommended every year for patients with asymptomatic severe aortic stenosis

• Every 3 to 5 years for mild AS

• Left ventricular dysfunction (EF < 50%) is a class II indication for surgery in asymptomatic patients with severe AS.⁵

• Low-gradient, low-output aortic stenosis

• Always consider this possibility in patients who have left ventricular dysfunction, severely reduced aortic leaflet mobility, but only a low aortic valve gradient (<30 mm Hg).

• Use low-dose dobutamine stress echocardiography to determine severity.

• Increase in stroke volume with increase in valve area greater than 0.2 cm² indicates that AS is unlikely to be severe.

• Increase in stroke volume with unchanged valve area and an increase in gradient are suggestive of severe AS.

• Lack of contractile reserve (<20% increase in stroke volume) is associated with a poor prognosis with either medical or surgical therapy.

Figure 2-13 Typical appearance of unicuspid (left), bicuspid (center), and quadricuspid (right) aortic valve.

Key Points

• Assess location, native valve morphology, and associated aortic disease.

• LVOT measurement can be challenging; errors are amplified in valve area calculations.

• Use all available windows and non-guided Doppler for gradient assessment.

• A dimensionless index can be helpful.

• Low-gradient, low-output AS is best assessed with low-dose dobutamine stress.

Aortic Regurgitation

• Aortic regurgitation (AR) is a disease characterized by volume overload of the left ventricle, resulting in progressive dilatation of the LV with typically preserved EF for a long duration of time.

• Eccentric jets of AR are difficult to quantify. The presence of large holodiastolic flow reversals in the thoracic and abdominal aorta is highly suggestive of severe AR (see Figure 2-14).

• Assess for signs of impending hemodynamic compromise in acute severe AR (early diastolic closure of the mitral valve, diastolic MR).

• Serial echocardiographic evaluation

• Recommended every 12 months for patients with asymptomatic severe AR and no evidence of LV dysfunction

• Whenever change in symptoms is suspected to be secondary to AR

• Contraindicated for routine follow-up of patients with mild AR

• Echocardiography-derived indications for surgery in asymptomatic patients with severe AR ⁵

• Class I: left ventricular dysfunction (EF < 50%)

• Class IIb: severe left ventricular dilatation (end-diastolic dimension > 70 mm, end-systolic dimension > 50 mm)

• Adjustment to body size is helpful, especially in women (less likely to develop left ventricular enlargement to that degree).

Figure 2-14 Severe AR resulting from a tear along the coaptation line of the left coronary cusp (top row, arrows). The jet is very eccentric (bottom, left panel), but excellent quantification by PISA method was possible from the deep transgastric view (bottom, middle panel). Also note prominent holodiastolic flow reversals in the descending thoracic aorta (bottom right, arrows). The patient underwent successful aortic valve repair.

Key Points

• Assess location of the obstruction, native valve morphology, and associated aortic disease (especially in bicuspid aortic valves).

• Large holodiastolic aortic flow reversals are consistent with severe AR.

• Diastolic MR and premature mitral closure are signs of impending hemodynamic compromise in patients with acute severe AR.

• Serial echocardiography is recommended in all patients with asymptomatic severe AR.

• Adjustment to body size is helpful, especially in women.

Myocarditis

• Viral infection is the most common cause of myocarditis. Non-infectious causes include toxic causes, hypersensitivity reactions, and systemic disorders.⁷

• Echocardiography is the most valuable method of assessment of LV dysfunction.

• Typical echocardiographic findings include:

• Reduced left ventricular EF

• Typically global hypokinesis, but RWMAs can also be present

• Occasionally exercise-induced RWMAs are seen and probably result from microvascular dysfunction.

• Fulminant myocarditis is associated with normal left ventricular diastolic dimensions, but increased septal thickness. If the patient survives, LV function frequently normalizes.

• Acute myocarditis is associated with a dilated left ventricle, but normal septal thickness. It may progress to persistent dilated cardiomyopathy.

• Strain and strain rate assessment may be useful, but large clinical studies are currently lacking.

Stress-Induced Cardiomyopathy (Tako-Tsubo, Apical Ballooning Syndrome)

• Stress-induced cardiomyopathy is transient systolic dysfunction of the apical and/or midsegments of the left ventricle that mimics myocardial infarction without evidence of obstructive coronary artery disease, usually occurring after emotional/physical stress or sometimes acute medical illness.⁸

• It is a diagnosis of exclusion, as infarction of a large left anterior descending coronary artery (LAD) that wraps around the apex can be associated with similar wall motion abnormalities.

• Postulated mechanisms are catecholamine surge, vasospasm, and microvascular dysfunction.

• The typical form (apical ballooning) has hypo/akinesis of the apical and midventricular segments, with compensatory hyperkinesis of the basal segments (Figure 2-15).

• The atypical form (midventricular ballooning) can occur in up to 40% of cases and involves the midventricular segments exclusively (Figure 2-16).

• Hyperdynamic function at the base can result in dynamic LVOT obstruction and acute MR as a result of systolic anterior motion of the mitral valve (see Figure 2-15).

• Most patients survive and have rapid recovery of LV function.

Figure 2-15 Apical long-axis views in a patient with stress-induced cardiomyopathy. Note typical hypo/akinesis of the apical and midventricular segments (left, end-diastolic frame; middle, end-systolic frame). In this patient who had pre-existing basal septal hypertrophy, hyperkinesis of the basal segments resulted in dynamic LVOT obstruction with severe systolic anterior motion of the mitral valve and severe posteriorly directed jet of MR (right).

Figure 2-16 Stress-induced cardiomyopathy, atypical form (midventricular ballooning). Note significant thickening of all ventricular walls from diastole (left frame) to systole (right frame). The only area that is akinetic is located in the midventricular wall on this MRI 4-chamber view (arrow). Coronary angiography was normal in this patient; there was no evidence of delayed enhancement on MRI.

Key Points

• Stress-induced cardiomyopathy is a transient disease related to emotional stress.

• It is a diagnosis of exclusion.

• Apical and mid-ventricular forms have been described.

• Functional MR can result from dynamic LVOT obstruction.

Tachycardia-Mediated Cardiomyopathy

• Essentially all forms of chronic tachyarrhythmia can induce left ventricular dysfunction.

• It is difficult to make the distinction as to whether the arrhythmia is the cause or consequence of the left ventricular dysfunction.

• A typical echocardiographic finding is the presence of left ventricular dysfunction (LV enlargement, reduced EF) in the context of tachyarrhythmia.

• Tachycardia-mediated cardiomyopathy is usually reversible with restoration of sinus rhythm or appropriate rate control.

Genetic Causes of Left Ventricular Dysfunction

Non-compaction Cardiomyopathy

• Non-compaction cardiomyopathy is a form of genetic cardiomyopathy.

• It is possibly due to intrauterine arrest of fetal myocardial primordium compaction.

• Other echocardiographic features:

• LV enlargement and decreased EF

• Intracardiac thrombi

• Abnormal papillary muscle structure

• Intravenous contrast is helpful for diagnosis and assessment of intracardiac thrombi.

Figure 2-17 Noncompaction cardiomyopathy. Note prominent trabeculations of the distal third of the ventricle (left: apical 2-chamber view; right: short-axis para-apical view).

Key Points

• Non-compaction cardiomyopathy is a genetic form of LV dysfunction characterized by deep LV trabeculations.

• It occurs in isolation or associated with other congenital diseases.

• Intravenous contrast is helpful.

Neuromuscular Disorders

• Duchenne muscular dystrophy

• In Duchenne muscular dystrophy, there is extensive fibrosis of the posterobasal LV wall, but this can extend to the free lateral wall with disease progression.

• There is frequently associated functional MR.

• Female carriers can have cardiac manifestation of the disease (Figure 2-18).

• Becker muscular dystrophy

• Cardiac involvement can be more severe than in Duchenne muscular dystrophy.

• Early involvement of the right ventricular wall is frequently seen.

• Other neuromuscular disorders (myotonic dystrophy, Barth syndrome, Emery-Dreifuss muscular dystrophy and Friedreich’s ataxia) are all associated with systolic LV dysfunction and conduction abnormalities.

Figure 2-18 Top, Regional wall motion abnormalities seen at rest (top row) and after exercise stress test (bottom row) in a female carrier of Duchenne muscular dystrophy. Bottom, Note the normal computed tomography appearance of the coronary arteries (left, LAD and circumflex; right, right coronary artery with posterior descending and posterolateral branches). Mild persistent creatine kinase elevation was noted.

Other Inherited Disorders

• Iron overload disorders

• Iron overload disorders are caused by hemochromatosis or hereditary sideroblastic anemias and thalassemias.

• Cardiac manifestation is part of a multi-organ disease, but can be the presenting feature.

• Echocardiographic features are those of typical dilated cardiomyopathy.

• Fabry’s disease

• Lysosomal storage disease

• Echocardiographic findings

• Left ventricular hypertrophy and LV dysfunction

• Presence of a hyper-echogenic endocardial stripe due to intracellular glycosphingolipid deposition in the endocardium (Figure 2-19)

Figure 2-19 Typical appearance of Fabry’s cardiomyopathy. There is mild left ventricular hypertrophy (septum measures 14 mm). Note the hyperechogenic endocardial stripe (arrows) seen both from the long-axis apical view (left panel) and the parasternal short-axis view (right). Left ventricular EF was still preserved in this patient.

1 Hunt SA, Abraham WT, Chin MH, et al. 2009 focused update incorporated into the ACC/AHA 2005 Guidelines for the Diagnosis and Management of Heart Failure in Adults: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines: developed in collaboration with the International Society for Heart and Lung Transplantation. Circulation. 2009;119:e391-e479.

This is the reference document of the American College of Cardiology and American Heart Association for evaluation of heart failure. It is a “must read.”

2 McMurray JJ. Clinical practice: Systolic heart failure. N Engl J Med. 2010;362:228-238.

Part of the Clinical Practice series in the New England Journal of Medicine. The article starts with a clinical vignette, and briefly reviews systolic heart failure from a clinical perspective, including the role of imaging.

3 Lang RM, Bierig M, Devereux RB, et al. Recommendations for chamber quantification: A report from the American Society of Echocardiography’s Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology. J Am Soc Echocardiogr. 2005;18:1440-1463.

The reference text for echocardiographic chamber quantification. Note that echocardiography boards frequently test candidates on this topic.

4 Enriquez-Sarano M, Akins CW, Vahanian A. Mitral regurgitation. Lancet. 2009;373:1382-1394.

A brief overview of the complex topic of MR, emphasizing the multiple types/mechanisms of this valvular disease. The reader will understand better what questions need to be answered when performing echocardiographic assessment of MR.

5 ACC/AHA 2006 Guidelines for the Management of Patients with Valvular Heart Disease: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2006;114:e84-e231.

The reference document of the American College of Cardiology and American Heart Association for valvular heart disease. While lengthy, it is certainly the most comprehensive effort on valvular disease, including brief aspects of surgical management. Watch for an update soon.

6 Peripartum cardiomyopathy: National Heart, Lung, and Blood Institute and Office of Rare Diseases (National Institutes of Health) workshop recommendations and review. JAMA. 2000;283:1183-1188.

Excellent review of this rare condition, with input from multiple disciplines (cardiovascular medicine, obstetrics, immunology, and pathology).

7 Cooper LTJr. Myocarditis. N Engl J Med. 2009;360:1526-1538.

Part of the Review series in the New England Journal of Medicine, this article is an excellent summary of the topic. It includes an overview of echocardiographic findings, but also of competing imaging modalities (MRI).

8 Prasad A, Lerman A, Rihal CS. Apical ballooning syndrome (Tako-Tsubo or stress cardiomyopathy): A mimic of acute myocardial infarction. Am Heart J. 2008;155:408-417.

A good review of stress-induced cardiomyopathy, including the role of imaging.

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