CLINICAL INVESTIGATION Idiopathic restrictive cardiomyopathy

This report details the clinical, hemodynamic, and morphologic data from four patients 59 to 77 years old (mean 66) with a primary restrictive cardiomyopathy. All patients had symptoms of congestive heart failure, jugular venous distention, and murmurs of mitral and tricuspid regurgitation. Four patients required pacemakers, three for the brady-tachy syndrome and one for complete heart block. Chest x-ray demonstrated cardiomegaly in all four patients and pulmonary congestion and/or pleural effusions in three. Echocardiographic examination documented left atrial enlargement in all patients, along with normal left ventricular internal dimensions. Global left ventricular systolic function was normal in all, and left and right ventricular filling pressures were elevated and similar in three. A dip and plateau pattern was present in the pressure tracings of two of three patients. Unlike previous reports of restrictive cardiomyopathy, in our four patients there was no specific morphologic cause noted at necropsy. Pathologic evaluation demonstrated biatrial dilatation in all patients, with thrombi present in the atrial appendages in three. Normal ventricular cavity size and mild right ventricular hypertrophy were present in all patients and mild-to-moderate left ventricular hypertrophy was present in two. There were no significant pericardial, endocardial, or valvular abnormalities and no infiltrative myocardial disorders were present. Light and electron microscopic studies demonstrated only interstitial fibrosis of the myocardium. A restrictive hemodynamic profile may be observed in the absence of specific infiltrative disorders and affected patients may exhibit a prolonged clinical course of 4 to 14 years (mean 9). However, in these patients congestive heart failure responded poorly to medical therapy or surgical correction of valvular regurgitation, which is common in this disorder. Circulation 70, No. 2, 165-169, 1984. RESTRICTIVE CARDIOMYOPATHY is a form of myocardial disease with a clinical and hemodynamic profile very similar to and frequently indistinguishable from that of constrictive pericardial disease. ' Clinical evidence of systemic venous congestion is frequently associated with hemodynamic evidence of elevated left and right heart filling pressures, including a "diastolic dip and plateau" configuration of ventricular pressure curves (square root sign).'o2Although the atria are frequently dilated, the ventricular cavities are usually normal in size and systolic performance as judged by ejection fraction is often well maintained. 1-3 The pathologic basis for most cases of restrictive cardiomyopathy includes infiltrative disorders such as amyloidosis, hemochromatosis, glycogen storage disease, mucopolysaccharidoses, endomyocardial fibrosis with or without eosinophilia, endocardial fibroelasFrom the Divisions of Cardiology and Anatomic Pathology. CedarsSinai Medical Center/UCLA School of Medicine. Los Angeles. Supported in part by NIH SCOR grant in Ischemic Heart Disease HL 17651. Address for correspondence: Robert J. Siegel. M.D.. Division of Cardiology, Room 5314. Cedars-Sinai Medical Center. 8700 Beverly Blvd.. Los Angeles, CA 90048. Received Jan. 11, 1984; revision accepted March 8. 1984. Vol. 70, No. 2, August 1984 tosis, sarcoidosis, and collagen-vascular diseases like scleroderma. 1-9 In this report we describe the clinical, hemodynamic, and morphologic data from four patients who presented with restrictive cardiomyopathy that was not associated with the usual pathologic entities responsible for this clinical-hemodynamic syndrome. Patients and methods The salient clinical characteristics of the four patients included in this report are summarized in table 1. Clinical presentation (table 1). All four patients presented with symptoms of biventricular failure. i.e.. dyspnea. pedal edema, and/or ascites that had been present for 4 to 8 years (mean duration 5 years). Antedating the onset of symptoms of congestive heart failure, complete heart block was noted in patient No. 1 14 years earlier and atrial arrhythmias were noted in patient No. 2 13 years earlier. One patient (No. 3) had a history of an isolated syncopal episode and two other patients (Nos. 2 and 4) had palpitations. Physical findings included those of jugular venous distention (in all patients), peripheral edema. ascites. and murmurs of mitral and tricuspid regurgitation. Electrocardiographic findings. All four patients had atrial fibrillation. One patient demonstrated paroxysms of supraventricular tachycardia and atrial fibrillation (No. 2). One patient also had complete heart block (No. 1). All patients required a permanent pacemaker. one for complete heart block and three 165 by gest on July 5, 2017 http://ciajournals.org/ D ow nladed from