History
Patients with restrictive cardiomyopathy (RCM) often present at an advanced stage of disease with pronounced cardiopulmonary symptoms. They complain of gradually worsening shortness of breath, progressive exercise intolerance, orthopnea, and fatigue. Paroxysmal nocturnal dyspnea may be reported.
Right-sided heart failure typically results in profound bilateral lower extremity edema, hepatomegaly, right upper quadrant pain, and ascites. Abdominal discomfort or liver tenderness may be reported.
Chest pain is rare, but it may be occur in amyloidosis or secondary to angina. Chest pain that mimics myocardial ischemia may be due to myocardial compression of small vessels. Patients may complain of frequent palpitations, as idiopathic RCM commonly causes atrial fibrillation. [19]
As many as one third of patients with idiopathic RCM may present with thromboembolic complications, especially pulmonary emboli secondary to blood clots in the legs. If atrial fibrillation is present, a high risk of left atrial clots and systemic emboli may also be present.
Patients may have a history of syncopal attacks from a variety of causes, but orthostatic hypotension secondary to a peripheral and/or autonomic neuropathy should be excluded. Syncope and sudden death are common in primary (amyloid light-chain [AL]) amyloidosis, but ventricular arrhythmias are uncommon. Electrical-mechanical dissociation is more usual. Conduction disturbances are particularly common in some forms of infiltrative RCM, but not in amyloidosis.
Depending on the etiology, patients may have a prior history of radiation therapy, heart transplantation, chemotherapy, or a systemic disease.
Physical Examination
A careful physical examination must be conducted to search for extracardiac manifestations of a systemic disorder that may cause secondary restrictive cardiomyopathy (eg, hemochromatosis, amyloidosis, sarcoidosis, or scleroderma). [11, 12] Particular attention should be paid to the cardiovascular and respiratory systems.
General examination
Patients may be more comfortable in the sitting position because of fluid in the abdomen or lungs, and they frequently have ascites and pitting edema of the lower extremities. The liver is usually enlarged and full of fluid, which may be painful. Weight loss and cardiac cachexia are not uncommon. Easy bruising, periorbital purpura, macroglossia, and other systemic findings, such as carpal tunnel syndrome, should be an indication for the clinician to consider amyloidosis. Amyloid infiltration may cause the liver to be enlarged and firm, but splenomegaly is rare.
Increased jugular venous pressure is present, with rapid x and y descents, and the most prominent finding is usually the rapid y descent. The degree of elevation of the jugular venous pressure indicates the severity of impaired filling of the right ventricle.
In constrictive pericarditis, the jugular venous pulse fails to fall during inspiration and may actually rise (Kussmaul sign). Although less common in restrictive cardiomyopathy (RCM), Kussmaul sign cannot be used as an absolute means to distinguish RCM and constrictive pericarditis. The pulse volume is decreased, consistent with decreased stroke volume and cardiac output.
Cardiovascular system examination
Heart sounds S1 and S2 are normal, with a normal S2 split. A loud early diastolic filling sound (S3) may be present, but it is uncommon in amyloidosis. A fourth heart sound (S4) is almost never present, possibly secondary to amyloid infiltration of the atria. Murmurs due to mitral and tricuspid valve regurgitation may be heard, but they are secondary to the myocardial disease and usually not hemodynamically significant.
Respiratory system examination
Breath sounds are often decreased due to pleural effusions, frequently bilateral and large in amyloidosis. Crepitations or rales are rarely heard, even in advanced heart failure of amyloidosis.
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Restrictive cardiomyopathy. Axial double inversion-recovery magnetic resonance image of the heart in a 30-year-old woman with sarcoidosis demonstrates a normal pericardium.
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Restrictive cardiomyopathy. Axial contrast-enhanced computed tomography scan through the heart (same patient as in the previous image) shows a thin pericardium without calcification. Note the cardiophrenic and internal mammary lymph nodes. The patient had extensive mediastinal and hilar adenopathy, as well as interstitial lung changes.
Tables
Clinical Features |
Constrictive Pericarditis |
Restrictive Cardiomyopathy |
History |
Prior history of pericarditis or condition that causes pericardial disease |
History of systemic disease (eg, amyloidosis, hemochromatosis) |
General examination |
… |
Peripheral stigmata of systemic disease |
Systemic examination - Heart sounds |
Pericardial knock, high-frequency sound |
Presence of loud diastolic filling sound S3, Low-frequency sound |
Murmurs |
No murmurs |
Murmurs of mitral and tricuspid insufficiency |
Prior chest radiograph |
Pericardial calcification |
Normal results of prior chest radiograph |
Investigation |
Constrictive Pericarditis |
Restrictive Cardiomyopathy |
Chest radiograph |
Pericardial calcification |
Atrial dilation causing increased cardiothoracic ratio; normal ventricular size |
CT scanning/MRI |
Pericardial thickening |
No pericardial thickening |
Echocardiography |
Normal-sized ventricles and atria; pericardial effusion may be observed |
Nondilated, normally contracting, nonhypertrophied ventricles and marked dilation of both atria |
Doppler flow velocities on echocardiography |
Respiratory changes (ie, decreased peak transmitral diastolic flow) during inspiration; equalization of the right- and left-sided filling pressures |
No respiratory changes; greater elevation in the left-sided filling pressures |
Catheterization hemodynamics: 1) RVSP 2) RVEDP:RVSP ratio 3) RVEDP/LVEDP equalization |
1) = 50 mm Hg 2) = 0.33 3) = 5-mm Hg difference |
1) = 50 mm Hg 2) = 0.33 3) = 5-mm Hg difference |
Cardiac biopsy |
Normal myocardium |
Often diagnostic, showing abnormal myocardium |
CT = computed tomography; LVEDP = left ventricular end-diastolic pressure; MRI = magnetic resonance imaging; RVEDP = right ventricular end-diastolic pressure; RVSP = right ventricular systolic pressure. |
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