Restrictive cardiomyopathy is a rare heart muscle disease that may affect both ventricles and is characterized by small ventricular cavity size, diastolic dysfunction, and elevated ventricular filling pressures.
Systolic function is usually normal, especially early in the coarse of the disease. Restrictive cardiomyopathy may result from various systemic disorders, as well as exposure to several toxins and chest radiation. Within the United States and Western Europe, this disease is most often secondary to amyloidosis. Patients with restrictive cardiomyopathy usually present with symptoms and signs of congestive heart failure, which on presentation make this disease process indistinguishable from more common forms of cardiomyopathy.
Signs of right-sided heart failure are usually prominent. The neck veins are distended and fail to collapse with inspiration or paradoxically rise(Kussmaul’s sign) secondary to impaired emptying of blood from the right atrium into the right ventricle. Peripheral edema, an enlarged liver, and ascites are also frequently present. On cardiac examination, the apical impulse is usually normal in location and intensity. An S3 originating from the right or left ventricle is frequently present. In advanced cases, the carotid impulse may be diminished in amplitude secondary to reduced stroke volume. The electrocardiogram may be normal in restrictive cardiomyopathy or only demonstrate nonspecific ST segment or T wave abnormalities. If the cardiomyopathy is secondary to an infiltrative process, such as amyloidosis , the ORS complexes may be diminished in amplitude(low voltage) and atrioventricular and interventricular conduction abnormalities may be present.
Echocardiography is helpful in excluding more common causes of congestive heart failure, and the Doppler examination may demonstrate abnormalities in diastole that are typical of a restrictive process.
However, right-sided heart catheterization is often necessary to confirm the diagnosis and differentiate this dideas process from constrictive pericarditis, which may present with similar clinica signs and symptoms.