Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Key Features ++ Rare; accounts for < 5% of all cases of cardiomyopathy Cause is usually idiopathic but can be familial or secondary to an infiltrative process (eg, amyloidosis) +++ Clinical Findings ++ Exercise intolerance Fatigue Chest pain Orthopnea Prominent S4 Jugular venous distention Signs of congestive heart failure as a consequence of diastolic dysfunction in the setting of preserved systolic function Left ventricle is more severely affected than the right ventricle, but the right ventricle is also affected in most cases resulting in signs and symptoms consistent with biventricular congestion +++ Diagnosis ++ Electrocardiography Demonstrates marked right and left atrial enlargement with normal ventricular voltages ST-T–wave abnormalities including a prolonged QTc interval may be present Echocardiography Presence of normal-sized ventricles with normal systolic function and massively dilated atria confirm diagnosis Cardiac MRI is useful in ruling out pericardial abnormalities (restrictive or constrictive pericarditis) and infiltrative disorders +++ Treatment ++ Anticongestive therapy is used for symptomatic relief Your MyAccess profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth