Andrew O. Zurick, III and Allan L. Klein
Diastolic dysfunction refers to a functional abnormality of myocardial relaxation, distensibility, or filling in the diastolic phase of the cardiac cycle. Heart failure with normal ejection fraction (HFNEF), previously referred to as diastolic heart failure, has increased in prevalence and now accounts for up to 50% of all cases of heart failure. To make the diagnosis of HFNEF, three conditions must be fulfilled: (a) the presence of symptoms or signs of heart failure, (b) the presence of normal or mildly abnormal systolic function, (c) evidence of diastolic left ventricular (LV) dysfunction. HFNEF is increasingly common and can be associated with significant morbidity and mortality, with comparable prognostic outlook among patients with heart failure with reduced ejection fraction (HFREF). Several pathophysiologic definitions of HFNEF have been proposed:
1. Impaired ventricular filling capacity without a compensatory increase in left atrial (LA) pressure
2. Abnormal ventricular filling resulting in inadequate cardiac output with a mean pulmonary venous pressure of <12 mm Hg
3. Resistance to filling of either or both ventricles with an inappropriate shift of the pressure–volume loop.
These definitions all have an abnormal resistance to filling, causing elevated left-sided filling pressures and congestion. Diastolic dysfunction impairs filling of the ventricle by impairing relaxation (early diastole), reducing compliance (early to late diastole), or by external constraint from the pericardium. Numerous pathologic processes and disease states may produce the clinical constellation of diastolic dysfunction. Ultimately, HFNEF is distinguished from HFREF, at the macroscopic level, by concentric LV remodeling, rather than eccentric.
PHYSIOLOGY OF DIASTOLE
Effective diastolic filling depends on the relationship between transmitral LA and LV pressures. Several factors influence this relationship: (a) active myocardial relaxation, (b) intrinsic passive LV compliance, and (c) extrinsic passive properties, including pericardial restraint and ventricular interaction.
PHASES OF DIASTOLE
Diastole is the period from the closure of the aortic valve to the termination of mitral inflow. It is divided into two periods: (a) an isovolumic relaxation period and (b) an auxotonic period that includes rapid filling, diastasis (slow filling), and atrial systole.
Isovolumic Relaxation Phase
The isovolumic relaxation time period occurs from the time of aortic valve closure to mitral valve opening during which there is active relaxation of the contracted myocardium generating a fall in LV pressure without a change in volume. There is active, energy-dependent myocyte relaxation until mid-diastole. Isovolumic relaxation ends when the LV pressure falls below the LA pressure, resulting in mitral valve opening, at which point the rapid filling phase commences.
Rapid Filling Phase
The auxotonic period occurs from mitral valve opening until mitral valve closure. When the LV pressure falls below LA pressure, the mitral valve opens, initiating the rapid filling phase. The elastic recoil and “untwisting” of the ventricle generated by myocardial relaxation creates a suction effect that augments the LA–LV pressure gradient, resulting in rapid filling of the ventricle. Blood acceleration occurs as a result of the development of an LA-to-LV pressure gradient. Blood rapidly enters the left ventricle from the left atrium during the early filling period. In normal hearts, approximately 70% to 80% of LV filling occurs during this phase of diastole. Rapid filling ends as atrial and ventricular pressures equalize.
Diastasis (Slow Filling) Phase
As rapid ventricular filling progresses, LV pressure gradually increases and briefly exceeds LA pressure, resulting in deceleration of mitral inflow and onset of diastasis. Diastasis typically accounts for <5% of filling.
Atrial Filling (Contraction) Phase
The onset of atrial contraction (atrial filling) in late diastole results in a brief increase in the transmitral gradient, forcing blood across the mitral valve and a small amount of regurgitation into the pulmonary veins. In normal hearts, this accounts for 20% to 25% of ventricular end-diastolic volume, with only a small rise in mean pulmonary venous pressure. Diastole ends and systole begins with the onset of ventricular contraction, resulting in a rapid increase in LV pressure that closes the mitral valve.
DETERMINANTS OF DIASTOLIC FUNCTION
Diastolic function depends on four major factors:
1. Active myocardial relaxation. This is mediated by intracellular ATP and calcium. Relaxation results from calcium sequestration into the sarcoplasmic reticulum by the calcium-ATPase pump after contraction. Abnormal relaxation may result from either elevated cytosolic levels of calcium in diastole or inadequate intracellular ATP levels. Factors that may affect isovolumic relaxation include internal loading forces, external loading states, and reduced or inhibited myocardial contractility.
2. Passive pressure–volume relationships (i.e., LV compliance). This is determined by the viscoelastic nature of the myocardium; chamber size, shape, and wall thickness; right and LV pressure–volume interaction; intrathoracic pressure; and pericardial restraint. As LV volume increases during diastole, an increase in LV pressure ensues. The slope of the pressure–volume curve during diastole (dP/dV) represents the chamber stiffness; and the inverse of this relation (dV/dP) is the chamber compliance (Fig. 21.1).
3. Left atrium (including atrial function), pulmonary vein, and mitral valve characteristics. In young, healthy, normal individuals, the atrial contribution is <20% of the total volume, whereas in older normal subjects, this atrial “kick” contributes a greater proportion of total LV filling.
4. Heart rate. As the heart rate increases, the diastolic filling period preferentially decreases with respect to the systolic ejection period.
FIGURE 21.1 Schematic representation of ventricular pressure–volume loops. The center panel demonstrates the normal situation. Note the exponential nature of the curve through late diastole. In systolic dysfunction (left), the end-systolic pressure line is displayed downward and is manifest by a decreased ability of the left ventricle to generate high pressures for a given volume. Diastolic dysfunction involves an upward and leftward shift of the exponential curve, a result of elevated filling pressures for a given volume. (Adapted from Katz AM. Influence of altered inotropy and lusitropy on ventricular pressure-volume loops. J Am Coll Cardiol. 1988;11:438–445.)
CLINICAL PRESENTATION
Recent consensus documents have now reported that nearly 50% of patients with heart failure have HFNEF. The clinical presentation of heart failure may include flash pulmonary edema and hypertensive heart disease, advanced ischemic heart disease, or hypertensive hypertrophic cardiomyopathy. Patients who often do not respond to heart failure treatment include patients with aortic stenosis, hypertrophic cardiomyopathy, infiltrative cardiomyopathy, and constrictive pericarditis. Typically, elderly patients with hypertension are at highest risk for developing the clinical syndrome of HFNEF. Signs and symptoms of HFNEF include the following:
1. Dyspnea on exertion and reduced exercise tolerance
2. With disease progression, patients may have dyspnea at rest, paroxysmal nocturnal dyspnea, and orthopnea.
3. Right-sided diastolic dysfunction can cause peripheral edema, bloating, and ascites.
PHYSICAL EXAMINATION
Physical examination cannot effectively separate patients with diastolic heart failure from those with systolic heart failure. Most patients with diastolic heart failure have hypertension or coronary artery disease. On auscultation, an audible S4 (stage I diastolic dysfunction by Doppler echocardiography, indicative of abnormal relaxation) or S3 (stage III diastolic dysfunction by Doppler echocardiography, indicative of reduced compliance) can be heard. There may be pulmonary rales, jugular venous distension, and edema.
LABORATORY EXAMINATION
ECG
The most common abnormality is an LV hypertrophy pattern. LA abnormality may also be seen.
Radiography
There are no specific findings on a chest x-ray. Pulmonary congestion with a normal cardiac silhouette suggests the presence of diastolic dysfunction.
Echocardiography
Echocardiography is the modality of choice to assess for diastolic dysfunction. Findings on an echocardiogram may include the following:
1. Normal LV systolic function and isolated diastolic dysfunction. Patients with abnormal systolic function have secondary diastolic function.
2. LV hypertrophy
3. LA enlargement. LA volume reflects the cumulative effects of filling pressures over time. Accurate measurements of LA volume are obtained using the apical 4-chamber and 2-chamber views, and this assessment is clinically important as there is a significant relationship between LA remodeling and echocardiographic indices of diastolic function. Previous observational studies have shown that LA volume index ≥ 34 m L/m2 is an independent predictor of heart failure, atrial fibrillation, ischemic stroke, and death.
4. Evidence of impaired ventricular filling. This has four stages (Fig. 21.2):
FIGURE 21.2 Stage I or impaired relaxation pattern, stage II or pseudonormal pattern, stage III or restrictive filling pattern, and stage IV or irreversible restrictive pattern. (Adapted from Garcia MJ, Thomas JD, Klein AL. New Doppler echocardiographic applications for the study of diastolic function. J Am Coll Cardiol. 1998;32:865–875.)
Stage I or impaired relaxation pattern. The time from the peak early (E) wave to the baseline (the deceleration time; DT) is prolonged to >220 milliseconds. The early/atrial (E/A ratio) is <1 and the isovolumic relaxation time is >100 milliseconds. Color M-mode flow propagation slope is <40 cm/s. Tissue Doppler annulus early velocity is <8 cm/s. In addition, the LA volume index should be increased, ≥34 cm/m2.
Stage II or pseudonormal pattern. This is associated with a normal appearance of the transmitral inflow pattern with an E/A ratio between 1 and 2, a DT between 150 and 220 milliseconds, and an isovolumic relaxation time between 60 and 100 milliseconds. To distinguish this from normal, the pulmonary venous pattern is analyzed and shows a prolonged and increased atrial reversal time >35 cm/s and the pulmonary venous systolic-to-diastolic flow is normal or <1. Color M-mode reveals a flow propagation slope <40 cm/s. Tissue Doppler annulus early velocity is <8 cm/s.
Stage III or restrictive filling pattern. There is reduced LV compliance. Elevated peak E-wave velocity and rapid deceleration are due to increased LV stiffness. The E/A ratio is >2, DT <150 milliseconds, and isovolumic relaxation time is <60 milliseconds. Color M-mode reveals flow propagation slope <40 cm/s, and tissue Doppler annulus early velocity is usually <8 cm/s.
Stage IV or irreversible restrictive pattern. This stage is similar to the findings of stage III, with no change in the Doppler pattern with preload-reducing maneuvers, and is associated with a substantially increased risk of death.
The modern assessment of diastolic function with echocardiography includes assessment of several Doppler parameters: (a) transmitral inflow velocities, (b) pulmonary venous flow velocities, (c) tissue Doppler mitral annulus velocities, (d) mitral inflow propagation velocities, and (e) Doppler estimation of pulmonary arterial pressures from tricuspid regurgitant flow velocities. Other echocardiographic parameters that sometimes contribute useful information regarding diastolic function include Tei index, B bump on mitral valve M-mode echocardiography, pulmonary valve regurgitant flow velocity, estimated pulmonary artery pressure from tricuspid regurgitant flow velocity, and size and respiratory change of the inferior vena cava. Doppler flow patterns can also be used to estimate LA and LV filling pressures. An increased E/A ratio, a shortened deceleration and isovolumic relaxation time, a decreased atrial filling fraction, a decreased pulmonary venous systolic fraction, an elevated and prolonged atrial reversal flow velocity, and increased LA volume may suggest an elevated mean LA pressure. By combining the mitral E wave, a variable that correlates modestly with LA pressure, and one that is associated with ventricular relaxation and is relatively preload independent (color M-mode propagation velocity or tissue Doppler echocardiography early filling velocity), closer approximations of LA pressure can be obtained. Algorithms for assessment of LV filling pressure and for grading diastolic dysfunction have been proposed in recent American Society of Echocardiography guidelines published in 2009 (Fig. 21.3). Additionally, now through the use of diastology stress testing, a grade 1 filling pattern can be changed to a grade 2 filling pattern with exercise or preload augmentation (Fig. 21.4).
FIGURE 21.3 A:An algorithm for assessment of LV filling pressure in patients with normal ejection fraction (EF). B: An algorithm for assessment of LV filling pressure in patients with depressed EF. C: Algorithm for grading diastolic dysfunction. Ar-A, difference in duration of the atrial reversal wave (pulmonary vein) and of the atrial wave of mitral inflow; LA, left atrial; Av, Average; LAP, normal left atrial pressure; ↑LAP, increased left atrial pressure; PAS, pulmonary arterial systolic pressure; IVRT, isovolumic relaxation time; DT, mitral inflow E wave deceleration time; Val, Valsalva; mitral inflow E velocity (E). e′, early diastolic velocity at the mitral annulus; Vp, flow propagation velocity; S/D, pulmonary venous systolic (S) and diastolic (D) flow wave ratio. (From Nagueh SF, Appleton CP, Gillebert TC, et al. Recommendations for the Evaluation of Left Ventricular Diastolic Function by Echocardiography. JASE. 2009;22:107–133, with permission from Elsevier.)
FIGURE 21.4 Diastolic stress echocardiography reflecting changes in exercise-induced diastolic filling pressures. Nagueh et al. showed that e′ remained unchanged with increased transmitral gradient in patients with diastolic dysfunction. (From Nagueh SF, Appleton CP, Gillebert TC, et al. Recommendations for the Evaluation of Left Ventricular Diastolic Function by Echocardiography. JASE 2009;22:107–133, with permission from Elsevier.)
PROGNOSIS
Despite earlier studies that suggested better outcomes among HFNEF patients compared with HFREF patients, more recent data suggest similar prognosis with both entities. Additionally, diastolic dysfunction, particularly of a moderate or severe degree, has now been shown to be a powerful predictor of increased morbidity and mortality (Fig. 21.5). It has been observed that 22% to 29% of patients with HFNEF die within 1 year of hospital discharge and 65% die within 5 years.
FIGURE 21.5 Kaplan-Meier survival curves for patients with heart failure and preserved or reduced ejection fraction. (Reprinted from Owan TE, Hodge DO, Herges RM, et al. Trends in prevalence and outcome of heart failure with preserved ejection fraction. N Engl J Med.2006;355:251–259, with permission from the Massachusetts Medical Society.)
TREATMENT OF DIASTOLIC HEART FAILURE
Treatment consists of reducing elevated filling pressures, maintaining atrial contraction, decreasing heart rate, preventing ischemia, improving relaxation, and implementing strategies to regress LV hypertrophy. Treatment is generally geared toward the management of the underlying pathologic condition in addition to the following:
1. Diuresis as needed to decrease central venous pressure
2. Beta-blockers to improve ventricular relaxation and enhance filling
3. Angiotensin-converting enzyme inhibitors (ACEIs), beta-blockers, calcium channel blockers, and other antihypertensives to decrease blood pressure and for afterload reduction
4. Restoration of normal sinus rhythm (NSR) in patients with atrial fibrillation and atrial flutter
The multicenter CHARM study has shown that treatment with Candesartan resulted in fewer readmissions for congestive heart failure with no difference in cardiovascular death or the combined endpoint of cardiovascular death or hospitalizations (Fig. 21.6). Additionally, data from the ancillary digitalis investigation group trial have shown that digoxin had no effect on mortality or all-cause of cardiovascular hospitalizations among patients with HFNEF already receiving ACEI and diuretics. The more recent, randomized, double-blind, placebo-controlled I-PRESERVE trial (Fig. 21.7) sought to determine if treatment with the angiotensin receptor blocker, irbesartan, reduced morbidity and mortality among 4,128 patients with HFNEF. Irbesartan did not reduce the composite primary endpoint of mortality or cardiovascular hospitalization.
FIGURE 21.6 Time to cardiovascular death or hospital admission for congestive heart failure in the CHARM study. (Reprinted from Yusuf S, Pfeffer MA, Swedberg K, et al. Effects of candesartan in patients with chronic heart failure and preserved left-ventricular ejection fraction: the CHARM-Preserved Trial. Lancet. 2003;362:777–781, with permission from Elsevier.)
FIGURE 21.7 Time to death from any cause or hospitalization for prespecified cardiovascular causes (worsening heart failure, myocardial infarction, stroke, atrial or ventricular arrhythmia, and myocardial infarction or stroke occurring during hospitalization for any cause) shown for patients receiving irbesartan and those receiving placebo in the i-PRESERVE trial. (Reprinted from Massie BM, Carson PE, McMurray JJ, et al. Irbesartan in patients with heart failure and preserved ejection fraction. N Engl J Med. 2008;359:2456–2467, with permission from the Massachusetts Medical Society.)
RESTRICTIVE CARDIOMYOPATHIES
Restrictive cardiomyopathy is defined as a disease of the myocardium, which is characterized by “restrictive filling and reduced diastolic volume of either or both ventricles with normal or near-normal systolic function.” Systolic function may be normal in the early stage of the disease, whereas wall thickness may be normal or increased depending on the etiology. The disease may be “idiopathic” or associated with other disease, such as amyloidosis.
Restrictive cardiomyopathies are recognized as primary and secondary, in which the secondary forms include the specific heart muscle diseases in which the heart is affected as part of a multisystem disorder—for example, infiltrative, storage, and noninfiltrative diseases. A “working classification” of restrictive cardiomyopathy is shown in Figure 21.8. Infiltrative cardiomyopathies can be further divided into interstitial and storage disorders. In interstitial diseases, the infiltrates localize to the interstitium (between myocardial cells), as with cardiac amyloidosis and sarcoidosis. In storage disorders, the deposits are within cells, as with hemochromatosis and glycogen storage diseases. These secondary forms of restrictive cardiomyopathies are probably more common than the primary form and display the classic restrictive hemodynamics only in their advanced form. The prototypical secondary restrictive cardiomyopathy is cardiac amyloidosis.
FIGURE 21.8 Working classification of restrictive cardiomyopathy. (From Leung DY, Klein AL. Restrictive cardiomyopathy; diagnosis and prognostic implications. In: Otto CM, ed. Practice of Clinical Echocardiography. Philadelphia: WB Saunders; 1997:474–493, with permission from Elsevier.)
Primary Restrictive Cardiomyopathies
Idiopathic restrictive cardiomyopathy is associated with familial transmission and skeletal myopathies. There is no specific pathology on endomyocardial biopsies. The atria are disproportionately large, with normal LV function. Histologic examination shows nonspecific degenerative changes seen in other cardiomyopathies, including interstitial fibrosis that may also occur in the sinoatrial and the atrioventricular nodes, causing possible heart block. Most small series show a protracted clinical course in adults, with a mean survival of 4 to 14 years (mean: 9 years).
Loffler endocarditis is associated with idiopathic hypereosinophilia. There is endocardial thickening, obliteration of the LV apex, and a high incidence of thromboembolism. Steroids and hydroxyurea may be helpful in management.
Endomyocardial fibrosis is endemic to tropical Africa. It occurs in the left and the right ventricular apices with obliteration and involvement of the subvalvular apparatus. Thromboembolism is common. Treatment is mainly palliative, although surgical debulking has been attempted, with increased surgical mortality.
Secondary Restrictive Cardiomyopathies
Amyloidosis is caused by deposition of insoluble proteins in the heart consistent with the “stiff heart” syndrome. Amyloidosis can be classified by the type of protein deposited. The primary type (AL type) is the most common (85% of the population). It is caused by fibrils composed of k- or λ-immunoglobulin light chains, often associated with multiple myeloma. Cardiac amyloidosis is mostly caused by primary amyloidosis (AL type). Secondary amyloidosis (AA type) is rare, with the fibrils consisting of protein A, a nonimmunoglobulin. Familial amyloidosis results from the production of a mutant prealbumin protein (transthyretin [TTR]). There are six different identified types that present with a cardiomyopathy, neuropathy, or nephropathy. In familial amyloidosis, cardiac involvement occurs in 28% of patients at the time of diagnosis; however, it usually presents late in the course of the disease.
Patients with cardiac amyloidosis present with HFNEF resulting from amyloid protein infiltration. Patients may present with various degrees of progressive biventricular heart failure, depending on the stage of disease, as shown by two-dimensional and Doppler echocardiography (Fig. 21.9). The prognosis can often be determined using Doppler echocardiography (Fig. 21.10). Treatment consists of chemotherapy and diuresis. Dose-intensive melphalan with autologous stem cell transplantation is currently being evaluated. Cardiac transplantation is generally not performed for patients with cardiac amyloidosis because this is a systemic illness with progressive extracardiac amyloid deposition.
FIGURE 21.9 Parasternal long (A) and short-axis (B) and apical long-axis (C) views show typical echocardiographic features of advanced cardiac amyloidosis. Note that LV size is normal with markedly thickened ventricular walls (ventricular septum = 22 mm, posterior wall = 18 mm, and right ventricular free wall = 15 mm) and its characteristic granular sparkling appearance. Small pericardial effusion (PE) and left pleural effusion (PLEFF) are also present. AO, aorta; AV, aortic valve; LA, left atrium; LV, left ventricle; PM, papillary muscle; RA, right atrium; RV, right ventricle; VS, ventricular septum. (From Klein AL, Oh JK, Miller FA, et al. Two-dimensional and Doppler echocardiographic assessment of infiltrative cardiomyopathy. J Am Soc Echocardiogr. 1988;1:48–59, with permission.)
FIGURE 21.10 Survival in 63 patients with cardiac amyloidosis subdivided on the basis of the deceleration time of 150 milliseconds. Patients with a shortened deceleration time of <150 milliseconds (bold line) had a significantly reduced survival compared with patient subgroup having deceleration time >150 milliseconds. (From Klein AL, Hatle LK, Taliercio CP, et al. Prognostic significance of Doppler measures of diastolic function in cardiac amyloidosis. A Doppler echocardiographic study. Circulation. 1991;83:808–816, with permission.)
Hemochromatosis can be primary, representing a recessive genetic disease, or secondary, due to iron overload (e.g., from blood transfusions). Phlebotomy may improve cardiac symptoms.
Storage disorders may be caused by a number of enzymatic defects that lead to accumulation of lipids or polysaccharides in the myocardium.
Sarcoidosis is a multisystem disease characterized histologically by the formation of granulomas in many tissues. Among patients dying with sarcoidosis, in whom autopsy is performed, noncaseating granulomas involving the myocardium are found in up to 25% of patients. Most patients are asymptomatic, but rhythm and conduction disorders may predominate. VT is the most common arrhythmia. Sudden death can occur in up to 17% of patients with extensive myocardial involvement. Steroid treatment is used for patients with conduction block or arrhythmias.
ACKNOWLEDGMENT
The authors wish to thank Oussama Wazni, MD, for his work on the previous version of this chapter.
SUGGESTED READINGS
Asher CR, Klein AL. Diastolic heart failure: restrictive cardiomyopathy, constrictive pericarditis, and cardiac tamponade: clinical and echocardiographic evaluation. Cardiol Rev. 2002;10:218–229.
Aurigemma GP, Gaasch WH. Diastolic heart failure. N Engl J Med. 2004;351:1097–1105.
Aurigemma GP. Diastolic heart failure—a common and lethal condition by any name. N Engl J Med. 2006;355:308–310.
European Study Group on Diastolic Heart Failure. How to diagnose diastolic heart failure. Eur Heart J. 1998;19(7):990–1003.
Gabriel RS, Klein AL. Modern evaluation of left ventricular diastolic function using Doppler echocardiography. Curr Cardiol Rep. 2009;11(3):231–238.
Klein AL, Asher CR. Diseases of the pericardium, restrictive cardiomyopathy and diastolic dysfunction. In: Topol EJ, ed. Textbook of Cardiovascular Medicine. 2nd ed. Philadelphia: Lippincott Williams & Wilkins; 2002:595–646.
Paulus WJ, Tschope C, Sanderson JE, et al. How to diagnose diastolic heart failure: a consensus statement on the diagnosis of heart failure with normal left ventricular ejection fraction by the Heart Failure and Echocardiography Associations of the European Society of Cardiology. Eur Heart J.2007;28:2539–2550.
Massie BM, Carson PE, McMurray JJ et al. Irbesartan in patients with heart failure and preserved ejection fraction. NEJM. 2008;359:2456–2467.
Nagueh SF, Appleton CP, Gillebert TC, et al. Recommendations for the Evaluation of Left Ventricular Diastolic Function by Echocardiography. JASE. 2009;22:107–133.
Vasan RS, Levy D. Defining diastolic heart failure: a call for standardized diagnostic criteria. Circulation. 2000;101:2118–2121.
Yamada H, Klein AL. Diastology 2010: clinical approach to diastolic heart failure. J Echocardiogr. 2010;8:65–79.
Yusuf S, Pfeffer MA, Swedberg K, et al. Effects of candesartan in patients with chronic heart failure and preserved left- ventricular ejection fraction: the CHARM-Preserved Trial. Lancet. 2003;362(9386):777–781.
Zile MR, Brutsaert DL. New concepts in diastolic dysfunction and diastolic heart failure: part 1, diagnosis, prognosis and measurements of diastolic function. Circulation. 2002;105: 1387–1393.
Zile MR, Brutasert DL. New concepts in diastolic dysfunction and diastolic heart failure: part ii. causal mechanisms and treatment. Circulation. 2002;105;1503–1508.
QUESTIONS AND ANSWERS
Questions
1. A 63-year-old male engineer undergoes echocardiography 2 months following a large posterolateral myocardial infarction due to acute stent thrombosis in his proximal left circumflex coronary artery.
Which of the following is associated with a better prognosis?
a. Ejection fraction (EF) of 29%
b. E/e′ of 23
c. Presence of moderate-to-severe mitral regurgitation (MR) with ERO = 0.3 cm2
d. Lateral wall e′ of 6 cm/s
e. Deceleration time of 133 milliseconds
2. The best two-dimensional (2-D) and Doppler echocardiographic finding to differentiate restrictive cardiomyopathy from constrictive pericarditis would be to evaluate:
a. Pulmonary venous flow pattern
b. Atrial size
c. Early diastolic mitral annular velocity
d. Mitral inflow pattern
e. Inferior vena cava dilatation
3. Which parameters are relatively preload independent?
a. Mitral inflow E wave
b. Tissue Doppler echo annular E′ wave
c. Color M-mode flow propagation velocity
d. Tissue Doppler echo annular E′ wave and color M-mode flow propagation velocity
4. Which of the following is the most common symptom associated with diastolic heart failure?
a. Chest pain
b. Paroxysmal nocturnal dyspnea
c. Exertional dyspnea
d. Dyspnea at rest
5. A 67-year-old obese woman is experiencing increasing dyspnea, fatigue, leg swelling and peripheral neuropathy that have developed over the past 9 months. Physical exam reveals a mildly distressed patient with visible dyspnea and 3+ bilateral leg edema. Auscultation is difficult and only distant heart sounds can be discerned. Electrocardiogram shows low voltage and a pseudoinfarct pattern. At this time, which is the best diagnostic study?
a. Echocardiogram with respirometry
b. Angiography
c. Cardiac CT scan
d. Cardiac MRI
Answers
1. Answer D: Regional ischemic injury will decrease the longitudinal systolic and diastolic excursion of the affected wall. Therefore, a lower value of e′ in the lateral wall of this patient is not an entirely unexpected finding (lateral e′ should normally be ≥10 cm/s). It is now recommended to acquire and measure tissue Doppler signals at least at the septal and lateral sides of the mitral annulus and calculate their average to measure E/e′. The other possible answers each have been shown to carry important prognostic information in patients with a history (recent or not) of myocardial infarction.
2. Answer C: Differentiating restrictive from constrictive pericarditis by echocardiography can be particularly challenging. Mitral inflow, pulmonary venous flow, or tricuspid inflow does not always exhibit the typical respiratory changes displayed in textbooks. The inferior vena cava (IVC) is commonly dilated in patients with constriction; however, this can also be seen in patients with advanced restrictive cardiomyopathy. Atrial size will usually be increased in patients with restrictive cardiomyopathy, but constrictive pericarditis will also eventually result in (particularly right-sided) atrial enlargement. In patients with restrictive cardiomyopathy, myocardial relaxation (e′) will be severely impaired; whereas in patients with constriction, annular vertical excursion will usually be preserved. A septal e′ velocity ≥7 cm/s has been shown to be highly accurate in differentiating patients with constrictive pericarditis from those with restrictive cardiomyopathy.
3. Answer D: Both tissue Doppler echocardiography annular E′ wave and color m-mode flow propagation are measures of relaxation and are relatively preload independent. Mitral inflow E wave is dependent on preload.
4. Answer C: Exertional dyspnea. With exertion, diastolic filling worsens and left ventricular (LV) filling pressure increases, resulting in dyspnea.
5. Answer A: Echocardiogram with respirometry. Echocardiography is the modality of choice for the initial assessment of cardiac amyloidosis.