Restrictive and Infiltrative Cardiomyopathies

Abstract The primary abnormality in restrictive cardiomyopathy (RCM) is diastolic dysfunction in the presence of preserved left ventricular ejection fraction, with gradually increasing left ventricular end diastolic and left atrial filling pressures. Restrictive cardiomyopathies may be either primary or secondary to other infiltrative or storage disorders. Diastolic functional assessment of myocardium using Doppler echocardiography plays an important role in its diagnosis. In addition, there is accumulating evidence of the diagnostic and prognostic role of speckle tracking in various conditions with RCM, even prior to the development of overt cardiomyopathy. Cardiac amyloidosis is characterized by increased symmetric left and right ventricular wall thickness with reduced ventricular cavities, a granular, sparkling texture of the myocardium, valvular, and interatrial septal thickening, and low voltage on electrocardiography. Cardiac amyloidosis demonstrates the characteristic “bull’s eye” pattern on speckle tracking, with preserved motion at the left ventricular apex and reduced motion at the ventricular base. Endomyocardial fibrosis, which is probably the most common cause of RCM worldwide, demonstrates endomyocardial fibrosis with apical obliteration of ventricular cavities, and formation of biventricular thrombi. Carcinoid syndrome is characterized by mural plaques and valvulitis with regurgitation and stenosis of the affected valves, especially the tricuspid and pulmonic valves. In addition, RCM should also be considered in patients post-chest radiation, or with the chemotherapy patient who presents with heart failure of unknown etiology.