Impaired Propagation Velocity In

Color Mode Flow Propagation Velocity

Fig. 6. Dilated cardiomyopathy: Mitral regurgitation. Mitral annular dilatation, lateral papillary muscle displacement, and apical tethering prevent normal leaflet coaptation. The result is typically mitral regurgitation (MR) with a centrally directed jet. Worsening MR heralds a worse prognosis. Color M-mode Doppler across the mitral valve (apical four-chamber view) during diastole provides a spatio-temporal display of blood velocities across the vertical interrogation line. This parameter may be less affected by loading conditions. The slope of this flow signal—flow propagation velocity (Vp)—is the slope of the first aliasing velocity measured on the E wave. Normal Vp is > 55 cm/s. Vp < 45cm/s may indicate impaired relaxation. (Please see companion DVD for corresponding video.)

Fig. 6. Dilated cardiomyopathy: Mitral regurgitation. Mitral annular dilatation, lateral papillary muscle displacement, and apical tethering prevent normal leaflet coaptation. The result is typically mitral regurgitation (MR) with a centrally directed jet. Worsening MR heralds a worse prognosis. Color M-mode Doppler across the mitral valve (apical four-chamber view) during diastole provides a spatio-temporal display of blood velocities across the vertical interrogation line. This parameter may be less affected by loading conditions. The slope of this flow signal—flow propagation velocity (Vp)—is the slope of the first aliasing velocity measured on the E wave. Normal Vp is > 55 cm/s. Vp < 45cm/s may indicate impaired relaxation. (Please see companion DVD for corresponding video.)

Infiltrative Cardiomyopathy

Fig. 7. Mitral inflow profiles showing evidence of diastolic dysfunction in dilated cardiomyopathy. The mitral inflow pulse Doppler profile in dilated cardiomyopathy often shows an impaired relaxation pattern (A) with prolonged deceleration time (DT > 200 ms) and reversal of the normal E:a ratio during the early stages. Later worsening of diastolic dysfunction is accompanied by a compensatory increase in left atrial filling pressures (driving pressure) results in early rapid filling of the left ventricle (a tall, thin E-wave) in the setting of a dilated left atrium. The marked fall in the A-wave velocity reflects atrial systolic dysfunction owing to a poorly compliant left ventricle.

Fig. 7. Mitral inflow profiles showing evidence of diastolic dysfunction in dilated cardiomyopathy. The mitral inflow pulse Doppler profile in dilated cardiomyopathy often shows an impaired relaxation pattern (A) with prolonged deceleration time (DT > 200 ms) and reversal of the normal E:a ratio during the early stages. Later worsening of diastolic dysfunction is accompanied by a compensatory increase in left atrial filling pressures (driving pressure) results in early rapid filling of the left ventricle (a tall, thin E-wave) in the setting of a dilated left atrium. The marked fall in the A-wave velocity reflects atrial systolic dysfunction owing to a poorly compliant left ventricle.

restrictive and infiltrative cardiomyopathy case presentation

A 76-yr-old male was admitted for investigation and management of decompensated heart failure. He presented earlier with a 3-mo history of progressive shortness of breath on exertion, paroxysmal nocturnal dyspnea, and ankle swelling. He denied any chest pain or palpitations. He gave no history of coronary artery disease. Both his previous coronary angiogram done in 1999 and a nuclear study in 2002 were reported as normal. His past medical history also includes aortic valve replacement in 5 yr earlier, paroxysmal atrial fibrillation, chronic obstructive pulmonary disease, essential thrombocytopenia, hypertension, and bilateral carpal tunnel syndrome. Significant investigations include an elevated brain natriuretic peptide levels, mild cardiomegaly on chest X-ray, and bilateral pleural effusions. His ECG

Left Atrial Wall Echocardiography

Fig. 8. Restrictive cardiomypathy: amyloid heart disease. Concentric left ventricular hypertrophy with reduction in left ventricular cavity size, dilated left atrium, left-sided pleural effusion (arrow, A), and smaller pericardial effusion (arrow, B) are features consistent with cardiac amyloidosis. Note thickened right ventricular wall and interatrial septum with moderate increase in right ventricular cavity size. A distinctive, but not specific sign of cardiac amyloidosis is the "ground-glass" or "sparkling" appearance of the myocardium (A-C). Right heart failure with increased right sided pressures are evident in this patient. Note the markedly dilated inferior vena cava (IVC, D). (Please see companion DVD for corresponding video.)

Fig. 8. Restrictive cardiomypathy: amyloid heart disease. Concentric left ventricular hypertrophy with reduction in left ventricular cavity size, dilated left atrium, left-sided pleural effusion (arrow, A), and smaller pericardial effusion (arrow, B) are features consistent with cardiac amyloidosis. Note thickened right ventricular wall and interatrial septum with moderate increase in right ventricular cavity size. A distinctive, but not specific sign of cardiac amyloidosis is the "ground-glass" or "sparkling" appearance of the myocardium (A-C). Right heart failure with increased right sided pressures are evident in this patient. Note the markedly dilated inferior vena cava (IVC, D). (Please see companion DVD for corresponding video.)

Amiloidosi Cardiaca Sparkling

Fig. 9. Restrictive cardiomypathy: amyloid heart disease. Doppler profiles in 76-yr-old male with decompensated heart failure and amyloid cardiomyopathy shows classic Doppler findings in restrictive cardiomyopathy (A). Right upper pulmonary venous flow with reduced systolic:diastolic flow ratio (B). Mitral inflow profile with increased E:a ratio < 2 (C). Markedly reduced velocities on Doppler tissue imaging (D). Blunted Vp slope on color flow propagation velocity M-mode.

Fig. 9. Restrictive cardiomypathy: amyloid heart disease. Doppler profiles in 76-yr-old male with decompensated heart failure and amyloid cardiomyopathy shows classic Doppler findings in restrictive cardiomyopathy (A). Right upper pulmonary venous flow with reduced systolic:diastolic flow ratio (B). Mitral inflow profile with increased E:a ratio < 2 (C). Markedly reduced velocities on Doppler tissue imaging (D). Blunted Vp slope on color flow propagation velocity M-mode.

Table 4 Restrictive Cardiomyopathy

Common Causes of Restrictive Cardiomyopathy

Primary Idiopathic

Hypereosinophilic syndrome (Löeffler endocarditis) Endomyocardial fibrosis Secondary Infiltrative disease:

amyloidosis (primary, secondary), sarcoidosis Post-radiation, carcinoid syndrome Storage diseases, hemochromatosis, glycogen storage diseases Diabetes mellitus (most common)

Table 5

Cardiomyopathies With Diastolic Dysfunction

Restrictive cardiomyopathy Dilated cardiomyopathy Hypertrophic cardiomyopathy Hypertensive cardiomyopathy Ischemic cardiomyopathy was notable for low-voltage QRS complexes and left bundle branch block.

Echocardiography study showed preserved left ventricular ejection fraction and echocardiogenic speckling suggestive of cardiac amyloid. His pulmonary artery pressure on echocardiography was estimated at 50 mmHg plus right atrial pressure. Selected still frames are shown in Figs. 8 and 9 (please see companion DVD for corresponding video for Fig. 8).

The restrictive cardiomyopathies are characterized by diastolic dysfunction because of poor ventricular compliance (reduced chamber distensibility). The underlying restrictive or infiltrative processes (Table 4), despite the specific etiology, typically lead to progressive biventricular stiffness and elevated filling (dias-tolic) pressures, manifesting clinically as exertional dysnea and right heart failure. Yet it is important to recognize that diastolic dysfunction is not specific to restrictive cardiomyopathy, and frequently accompanies other cardiomyopathies that are not primarily restrictive (Table 5).

The diagnosis of restrictive cardiomyopathy is primarily clinical, but 2D and Doppler echocardiography play supportive/confirmatory roles (Table 6). Left ventricular cavity size is characteristically preserved, but wall

Table 6

A Summary of Echocardiography Findings in Restrictive Cardiomyopathies

Modality

Findings

Two-dimensional findings

Doppler findings

Mitral inflow

Pulmonary vein

Doppler tissue imaging Color M-mode (flow propagation velocity; Vp)

Normal ventricular volumes, preserved systolic function, marked biatrial enlargement Limited (<20%) variation in inflow velocities with respiration (compared with constrictive pericarditis) Reduced isovolumic relaxation time

(<70 m/s) Increased E velocity (>1 m/s) Reduced deceleration time (<160 ms) Reduced A velocity (<0.5 m/s) Reduced A wave duration Increased E:a ratio (>2) Reduced systolic flow Increased diastolic flow Reduced systolic:diastolic flow ratio Increased peak atrial reversal velocity and duration Reduced Em velocity (lateral annulus), <8-10 cm/s Quantitative: Vp < 45 cm/s (quantitative) (normal >55 cm/s) visual estimate: blunted Vp slope (normal ~90°, upright)

thicknesses may be normal, increased, or even decreased. In amyloid heart disease, the prototype restrictive cardiomyopathy, concentric left ventricular thickening is typical and systolic function preserved (until the advanced stages). The pattern of myocardial wall thickening (involving the right ventricle and intera-trial septum) are clues to the diagnosis (Table 7). Right ventricular dilatation frequently occurs and biatrial enlargement is almost always present. In addition, a small pericardial effusion and nonspecific valvular thickening are common. A "ground-glass" or "sparkling" appearance of ventricular myocardium is distinctive, but nonspecific for amyloid. However, when combined with other echocardiographic findings, it is highly suggestive of amyloid.

A helpful confirmatory parameter in cardiac amyloid is assessment of the voltage-to-mass ratio. Amyloid infiltration of the myocardium increases ventricular mass (Fig. 10) while reducing QRS voltage. This finding may be characteristic of amyloid and

Table 7

Echocardiography Findings in Amyloid Heart Disease

Modality

Description

Two-dimensional/ Left ventricular hypertrophy M-mode findings (with low QRS voltages or pseudoinfarct pattern on electrocardiogram), diminution of left ventricular cavity size, right ventricular hypertrophy, distinctive "ground-glass or sparkling" appearance of myocardium (nonspecific), thickened inter-atrial septum and valve leaflets, biatrial enlargement, echocardiographic signs of right heart failure, multi-valvular regurgitation; small to moderate pericardial effusion, LV function usually preserved until advanced stages Doppler findings Diastolic dysfunction (commonest and earliest abnormality), restrictive cardiomyopathy Doppler profile other infiltrative disease, and distinguish it from other causes of increased wall thickness, such as hypertensive hypertrophy or hypertrophic cardiomyopathy.

Doppler profiles found in restrictive cardiomyopathy (Table 6) reveal abnormal diastolic filling patterns (see also Chapter 6). Reduced ventricular compliance (increasing ventricular stiffness) requires greater filling pressures, i.e., elevated ventricular end-diastolic pressures and markedly increased atrial pressures.

In the early stages, an impaired relaxation pattern predominates (Fig. 7 A). Early rapid filling is slowed (decreased peak E velocity with prolonged DT) and increased atrial filling (kick) is required to compensate. E:a reversal or E:a ratio less than 1 and DT greater than 200 m/s defines the condition. Over time, increased early rapid filling is restored as higher filling pressures generated by a now dilated/thickened atria compensate and manifests as a "pseudonormalized" pattern. Repeat recordings during stage 2 of the Valsalva maneuver can unmask pseudonormalization—this acutely reduces filling pressures and reveals the underlying impaired relaxation. Pulmonary venous flow patterns provide supportive evidence. As the pathological processes ensue, a restrictive pattern becomes established (Fig. 9). The tall steep E-wave reflects higher transmitral gradients with very rapid equilibration during early diastole. Deteriorating atrial function frequently leads to atrial fibrillation (absent A-wave) or a markedly diminished

Amyloid Heart Biatrial Enlargement

Fig. 10. Restrictive cardiomyopathy: amyloid heart disease. Gross heart specimen from a 66-yr-old man patient with systemic amyloidosis who died from congestive heart failure. Heart weighed 650 g (adjusted normal <350 g). Note thickened left ventricle with reduced cavity size, dilated atria, and intracardiac device. Biatrial enlargement reflects the consequences of impaired ventricular filling—a characteristic of restrictive cardiomyopathies.

Fig. 10. Restrictive cardiomyopathy: amyloid heart disease. Gross heart specimen from a 66-yr-old man patient with systemic amyloidosis who died from congestive heart failure. Heart weighed 650 g (adjusted normal <350 g). Note thickened left ventricle with reduced cavity size, dilated atria, and intracardiac device. Biatrial enlargement reflects the consequences of impaired ventricular filling—a characteristic of restrictive cardiomyopathies.

A-wave (E:a ratio >1 and DT <150 ms). The most reliable diastolic abnormality by echocardiography is reduced myocardial relaxation velocities. Patients with advanced restrictive heart disease, such as amyloid, can have lateral mitral annular diastolic velocities of 5 cm/s or less (see Chapter 6).

The more common etiologies for restrictive cardio-myopathy are: (1) cardiac amyloid, which is the most common cause in the industrialized world; (2) hypere-osinophilic syndrome and endomyocardial fibrosis, common in parts of Latin America, Asia, and Africa; (3) carcinoid heart disease (see Chapter 19); (4) Sarcoi-dosis (sarcoid granulomata primarily affect the retic-ulo-endothelial system, the lungs, and skin, but cardiac involvement occurs). Right heart failure may be a sequel to pulmonary fibrosis, but sarcoid granulo-matous infiltration of the heart can lead to a restrictive cardiomyopathy as well as impaired systolic function and conduction disturbances (Fig. 11).

Restrictive cardiomyopathy can resemble, and can be difficult to distinguish from, constrictive pericarditis. Preservation of systolic function and abnormal diastolic filling patterns are seen in both. However, a thickened pericardium and respirophasic variation in inflow velocities are indicative of constrictive pericarditis (Fig. 12). In addition, mitral annular diastolic relaxation velocities are typically normal in patients with constrictive

Cardiac Sarcoidosis Echocardiographic

Fig. 11. Restrictive cardiomypathy: cardiac sarcoid. Echocardiography images and a gross heart specimen from a 58-yr-old female who succumbed to complications related to severe pulmonary sarcoid, pulmonary fibrosis, and bronchiectasis are shown. In addition to Doppler indices consistent with a restrictive cardiomyopathy, biatrial enlargement and right ventricular hypertrophy secondary to pulmonary hypertension were seen (A-D).

Fig. 11. Restrictive cardiomypathy: cardiac sarcoid. Echocardiography images and a gross heart specimen from a 58-yr-old female who succumbed to complications related to severe pulmonary sarcoid, pulmonary fibrosis, and bronchiectasis are shown. In addition to Doppler indices consistent with a restrictive cardiomyopathy, biatrial enlargement and right ventricular hypertrophy secondary to pulmonary hypertension were seen (A-D).

Respirophasic Flow

Fig. 12. Doppler indices: constrictive pericarditis vs restrictive cardiomyopathy. Simplified schema integrating Doppler profiles of mitral inflow, Doppler tissue imaging, and respirophasic changes to distinguish constrictive pericarditis from restrictive cardiomyopathy. Other Doppler profiles of tricuspid valve flow (Chapter 10, Fig. 12), pulmonary venous flow, and hepatic venous flow, should be integrated to improve assessment. However, the basis of the distinction remain the clinical presentation, two-dimensional echocardiographic findings, and computed tomography /magnetic resonance imaging.

Fig. 12. Doppler indices: constrictive pericarditis vs restrictive cardiomyopathy. Simplified schema integrating Doppler profiles of mitral inflow, Doppler tissue imaging, and respirophasic changes to distinguish constrictive pericarditis from restrictive cardiomyopathy. Other Doppler profiles of tricuspid valve flow (Chapter 10, Fig. 12), pulmonary venous flow, and hepatic venous flow, should be integrated to improve assessment. However, the basis of the distinction remain the clinical presentation, two-dimensional echocardiographic findings, and computed tomography /magnetic resonance imaging.

physiology, whereas quite abnormal in patients with restrictive disease.

Clinically silent diastolic and systolic dysfunction eventually occurs in most patients with diabetes mellitus, even in well-controlled individuals. Diabetic cardiomyopathy is increasingly recognized as perhaps the most prevalent type of restrictive cardiomyopathy.

hypertrophic cardiomyopathy case presentation

A 27-yr-old Caucasian male presented with episodes of palpitations. He gave no history of prescription drug or illicit drug use or smoking and led a physically active lifestyle. Family history was significant for hypertrophic cardiomyopathy. Physical examination was completely normal, including cardiac examination at rest and during Valsalva maneuver. His ECG showed normal sinus

Interventricular Septum Hypertrophy

Fig. 13. Case presentation: hypertrophic cardiomyopathy. Thickened interventricular septum (IVS) measuring 20 cm, normal posterior wall thickness, and normal chamber sizes are seen on parasternal long-axis (PLAX) view (A). M-mode at the mitral valve level shows the hypertrophied septum with E-point septal contact (B). Parasternal short-axis view confirms assymetric hypertrophy (C), which most often spares the basal posterior wall as shown on this M-mode through the short-axis view at the mitral level (D). (Please see companion DVD for corresponding video.)

Fig. 13. Case presentation: hypertrophic cardiomyopathy. Thickened interventricular septum (IVS) measuring 20 cm, normal posterior wall thickness, and normal chamber sizes are seen on parasternal long-axis (PLAX) view (A). M-mode at the mitral valve level shows the hypertrophied septum with E-point septal contact (B). Parasternal short-axis view confirms assymetric hypertrophy (C), which most often spares the basal posterior wall as shown on this M-mode through the short-axis view at the mitral level (D). (Please see companion DVD for corresponding video.)

rhythm, heart rate of 67 bpm, normal intervals, and normal axis. Right ventricular conduction delay, left ventricular hypertrophy (LVH), and repolarization abnormalities were present.

On echocardiography, his left ventricular size was normal with normal left ventricular function and ejection fraction 70-75% (Figs. 13 and 14, please see companion DVD for corresponding video). No regional wall motion abnormalities were present but marked septal hypertrophy with maximal wall thickness of 24 mm (proximal-midseptum) was noted. Only minor systolic anterior motion (SAM) of the mitral chords was seen. No significant intracavitary gradient was detected either at rest or with the Valsalva maneuver. Reversed curvature of the interventricular septum was seen. The aortic root and leaflets were normal but trace aortic regurgitation was present. The right ventricle, tricuspid valve, and both atria were normal in size and function. The inferior vena cava and the pericardium were normal.

Hypertrophic cardiomyopathy is typically defined as unexplained ventricular hypertrophy, and can be generally diagnosed in a patient with hypertrophy not associated with hypertension or other obvious causes, such as aortic stenosis. The majority of cases of hypertrophic cardiomyopathy are caused by sarcomeric genetic mutations, although many specific gene mutations have been identified. Approximately 50% of cases are autosomal dominant.

Hypertrophic cardiomyopathy exhibits great heterogeneity both in morphological appearance and clinical presentation. Most patients with hypertrophic cardiomyopathy present clinically between ages 20 and 40 yr. Presentation later in life is generally associated with less severe forms of the disease.

Echocardiography has great utility in hypertrophic cardiomyopathy (Table 8). It helps establish the diagnosis in symptomatic patients, and exclude secondary causes of ventricular hypertrophy. It is an essential screening tool in identifying and monitoring relatives of affected patients. 2D, M-mode, and stress echocardiography are indispensable for v L k

Wave Echocardiography

Fig. 14. Case presentation: hypertrophic cardiomyopathy. Spectral Doppler profiles of patient in our case presentation shows normal Doppler profiles in the evaluation of pulmonary venous flow, mitral inflow, and Doppler tissue imaging at the lateral mitral annulus (A-C). Pulse Doppler interrogation along the septum using apical windows showed no stepwise increase in gradient (D,E). Continuous-wave Doppler evaluation confirmed the same (E).

Fig. 14. Case presentation: hypertrophic cardiomyopathy. Spectral Doppler profiles of patient in our case presentation shows normal Doppler profiles in the evaluation of pulmonary venous flow, mitral inflow, and Doppler tissue imaging at the lateral mitral annulus (A-C). Pulse Doppler interrogation along the septum using apical windows showed no stepwise increase in gradient (D,E). Continuous-wave Doppler evaluation confirmed the same (E).

Table 8

Utility of Echocardiography in Hypertrophic Cardiomyopathy

1. Definitive diagnosis; excludes secondary causes, e.g., aortic stenosis

2. Screening tool for first-degree and other relatives

3. Assessment of morphological variants—and distribution and magnitude of left ventricular outflow tract gradients

4. Assessment of mitral regurgitation severity (when present)

5. Evaluation of diastolic function

6. Patient selection for intervention procedures e.g., septal ablation or surgical myotomy-myectomy (stress echocardiography and other maneuvers)

7. Myocardial contrast echocardiography: improves success rate of septal ablation and reduce need for permanent pacing

8. Monitoring and follow-up postmedical or surgical intervention detecting dynamic outflow tract obstruction and its various components, as well as in the assessment of provocative maneuvers. Intraprocedural myocardial contrast echocardiography can improve the success rates of septal ablation procedures for hypertrophic cardiomyopathy.

Echocardiographic Findings

Echocardiographic features of the most common variant—assymetric septal hypertrophy—includes marked hypertrophy along the length of the entire inter-ventricular septum, often at the expense of the left ventricular cavity and normal or increased ventricular systolic function. Often, the septal-to-posterior wall thickness ratio is greater than 1.3, although it is also not uncommon to find relatively concentric hypertrophy. Reversed curvature of the interventricular septum is a typical finding in hypertrophic cardiomyopathy. Typically, hypertrophy extends down the majority of the length of the septum and is distinct from upper septal disproportionate thickening common in hypertensive hypertrophy of the elderly.

A typical feature of the enlarged interventricular septum is its impact on the Doppler profile of the left ventricular outflow tract (LVOT). This "dagger-shaped" spectral Doppler pattern reflects late-peaking systolic flow through

Hypertrophy Interventricular Septum

Fig. 15. Hypertrophic cardiomyopathy: variants. Hypertrophic cardiomyopathy morphology exhibits heterogeneity. The most common variant is assymetric septal hypertrophy involving the entire septum (B). Discrete upper septal hypertrophy displays a sigmoid-shaped septum (C). It is not the same as discrete/disproportionate upper septal thickening (DUST) or "septal knuckle" often seen in the elderly. The apical variant of hypertrophic cardiomyopathy (D) was first described in Japan, but occurs globally. The left ventricular chamber assumes an "ace of spades" configuration and is best seen in the apical 4-chamber view. It must be differentiated from left ventricular noncompaction. The concentric pattern of hypertrophic cardiomyopathy (E) occurs, exhibiting symmetrical thickening of the entire left ventricular wall. Concentric left ventricular hypertrophy with pressure overload states can be confused with this variant. Hypertrophied papillary muscles or midventricular hypertrophic cardiomyopathy is an uncommon variant. It may be associated with midcavity obstruction.

Fig. 15. Hypertrophic cardiomyopathy: variants. Hypertrophic cardiomyopathy morphology exhibits heterogeneity. The most common variant is assymetric septal hypertrophy involving the entire septum (B). Discrete upper septal hypertrophy displays a sigmoid-shaped septum (C). It is not the same as discrete/disproportionate upper septal thickening (DUST) or "septal knuckle" often seen in the elderly. The apical variant of hypertrophic cardiomyopathy (D) was first described in Japan, but occurs globally. The left ventricular chamber assumes an "ace of spades" configuration and is best seen in the apical 4-chamber view. It must be differentiated from left ventricular noncompaction. The concentric pattern of hypertrophic cardiomyopathy (E) occurs, exhibiting symmetrical thickening of the entire left ventricular wall. Concentric left ventricular hypertrophy with pressure overload states can be confused with this variant. Hypertrophied papillary muscles or midventricular hypertrophic cardiomyopathy is an uncommon variant. It may be associated with midcavity obstruction.

the LVOT (Fig. 15). Echocardiography features found in hypertrophic cardiomyopathy are summarized in Table 9 and Figs. 16 and 17.

LVOT Obstruction and SAM of the Mitral Valve

Marked narrowing of the LVOT is seen or inducible in about one-fourth of patients. The result is dynamic LVOT obstruction (Fig. 18; please see companion DVD for corresponding video). This involves more than obstruction caused by the hypertrophied septum. SAM of the anterior mitral valve leaflet and abnormalties of the entire mitral valve complex commonly occur (Table 10). Enlarged elongated mitral leaflets and abnormalities of the subvalvular apparatus—papillary muscles and chordal attachments— all participate in the septal anterior motion and outflow tract obstruction. A posteriorly directed mitral regurgitant jet typically accompanies SAM.

SAM of the mitral valve (Figs. 18 and 19; please see companion DVD for corresponding video) is not pathog-nomonic of hypertrophic cardiomyopathy; it occurs in

Table 9

Echocardiographic Findings in Hypertrophic Cardiomyopathy

Modality

Description

Two-dimensional findings

Asymmetric; isolated septal hypertrophy (commonest variant), although concentric hypertrophy also common

Septal: Posterior wall thickness ratio >1.3 elongated mitral leaflets—coaptation point along the body, not the tips of leaflets (Figs. 18 and 19)

SAM of mitral valve; midsystolic notching/fluttering of the aortic valve

Dynamic LVOT obstruction; "dagger-shaped" CW profile; mitral regurgitant (accompanying SAM) with posteriorly directed jet; relaxation abnormality/ diastolic dysfunction

LVOT, left ventricular outflow tract; CW, continuous wave; SAM, systolic anterior motion.

M-mode

Doppler findings

Left Atrial Wall Echocardiography

Fig. 16. Hypertrophic cardiomyopathy: concentric variant. Hypertrophic cardiomyopathy of the concentric variety in a 38-yr-old male who succumbed to surgical complications unrelated to his cardiomyopathy. Note the massive hypertrophy confined to the left ventricle and marked dilatation of his left atrial chamber.

Fig. 16. Hypertrophic cardiomyopathy: concentric variant. Hypertrophic cardiomyopathy of the concentric variety in a 38-yr-old male who succumbed to surgical complications unrelated to his cardiomyopathy. Note the massive hypertrophy confined to the left ventricle and marked dilatation of his left atrial chamber.

Table 10

Factors Contributing to Dynamic Left Ventricular Outflow Trait Obstruction

1. Septal hypertrophy

2. Systolic anterior motion of mitral valve leaflets

3. Systolic anterior displacement of entire mitral valve complex (including papillary muscles)

4. Redundant mitral valve leaflets

5. Hydrodynamic drag forces (Venturi effect)

secondary hypertrophic cardiomyopathies and hyper-contractile states (Table 11). The time of onset and the duration of SAM are best appreciated on M-mode echocardiography. Both such measurements are related to the severity of LVOT obstruction (Fig. 20).

A midsystolic drop in LVOT velocities—a reflection of impedance to flow within the aorta—typically manifests as midsystolic notching and fluttering of the aortic valve leaflets on M-mode ("lobster claw abnormality," Fig. 21). Dynamic outflow obstruction may be absent at rest, but provoked by maneuvers that reduce preload (e.g., Valsalva maneuver

Hypertrophic Cardiomyopathy Valsalva
Fig. 17. Hypertrophic cardiomyopathy. Spectral Doppler profile of characteristic "dagger-shaped" flow distal to the hypertrophied septum. This reflects late peaking maximal velocities—a manifestation of some obstruction to systolic flow.

or amyl nitrite inhalation (Table 12; Fig. 22); or increased by maneuvers that increase preload, such as simple leg lifting.

Dynamic outflow obstruction is best appreciated on continuous-wave Doppler. Interrogation of velocities across the LVOT produces a characteristic late-peaking Doppler profile. Using the simplified Bernoulli equation, peak velocities can be converted into pressure gradients across the LVOT. Exercise provokes increased LVOT gradients and exercise stress echocar-diography may provide better correlation between symptoms and disease severity compared to amyl nitrite inhalation (Table 12, Fig. 23A).

A similar pattern of dynamic outflow tract obstruction can be seen in midcavity obstruction owing to variant hypertrophic cardiomyopathy (Fig. 23B). The discrete or disproportionate upper septal hypertrophy ("DUST") commonly seen in elderly individuals bears

Fig. 18. Dynamic left ventricular outflow tract obstruction. Dynamic left ventricular outflow tract obstruction with systolic anterior motion of the mitral valve leaflets (SAM) are shown in this parasternal long-axis (PLAX) view (A). Suboptimal mitral leaflet coaptation accompanies SAM and is typically accompanied by a posteriorly directed mitral regurgitant jet. Note the turbulence created in within the left ventricular outflow tract (arrow, B). Apical five-chamber (A5C) views of the same features above are shown (D). (Please see companion DVD for corresponding video.)

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