Snapshot A 40-year-old woman presents to her physician’s office for dyspnea on exertion and exercise intolerance. She states that her symptoms seem to be worsening over time. Her medical history includes breast cancer. A year prior to presentation, she had completed multiple rounds of chemotherapy and radiation therapy for her breast cancer. Echocardiogram shows diastolic dysfunction with preserved systolic function. Introduction Clinical definition a cardiomyopathy characterized by a stiff myocardium and diastolic dysfunction Epidemiology Incidence least common type of cardiomyopathy Demographics can occur in both children and adults Etiology Pathogenesis rigid noncompliant myocardium (e.g., from amyloid deposition, sarcoidosis, or radiation) impedes ventricular filling and causes diastolic dysfunction typically preserved left ventricular systolic function mimics constrictive pericarditis Post-radiation fibrosis Loffler endocarditis endomyocardial fibrosis with a prominent eosinophilic infiltrate can be associated with large mural thrombi and peripheral hypereosinophilia Endocardial fibroelastosis in children and young adults Amyloidosis Sarcoidosis Scleroderma Neoplasia Hemochromatosis more commonly causes dilated cardiomyopathy but can also cause restrictive cardiomyopathy Radiation therapy can result in pericarditis, myocarditis, coronary artery narrowing, and sclerotic valvular changes Presentation Symptoms progressive heart failure dyspnea on exertion exercise intolerance fatigue sudden cardiac death Physical exam edema hepatomegaly ascites pulmonary rales S3 gallop jugular venous distension Kussmaul sign increase in jugular venous pressure during inhalation Imaging Radiography indication for all patients recommend views chest findings cardiomegaly pulmonary congestion Echocardiogram indication for all patients as diagnostic test findings thickening of all structures diastolic dysfunction preserved systolic function Studies Electrocardiogram findings may have low-voltages Endomyocardial biopsy indication the most accurate diagnostic test of etiology tissue biopsy needed to diagnose amyloidosis (apple-green birefringence on Congo Red stain) or Loffler syndrome findings eosinophilic infiltrate in Loffler syndrome amyloid deposits in cardiac amyloidosis Making the diagnosis based on clinical presentation, echocardiogram, and biopsy Differential Constrictive pericarditis distinguishing factors patients with a history of acute pericarditis or cardiac surgery pericardial knock on exam chest radiography shows calcification computed tomography shows thickened pericardium Dilated cardiomyopathy distinguishing factors echocardiogram with reduced ejection fraction progressive heart failure Treatment Management approach treatments are aimed at managing symptoms and treating underlying etiology Medical diuretics indication symptomatic management of congestive heart failure Non-operative phlebotomy indication for patients with hemochromatosis Operative heart transplant indication the only definitive treatment Complications Heart failure Arrhythmias Prognosis Poor prognosis without treatment Progressive over time