PROGRESSIVE RESTRICTIVE CARDIOMYOPATHY - A CASE-REPORT

We present a case of restrictive cardiomyopathy which progressed over a 10 month period. A 69-year-old female was admitted because of acute inferior myocardial infarction; hemodynamically, she was in Forrester subset I. Cardiac catheterization performed 4 weeks post-infarction showed markedly increased left ventricular end-diastolic and pulmonary wedge pressures. Left ventricular ejection fraction was 66% with postero-basal akinesis and minimal mitral regurgitation. The right coronary artery was completely occluded with good collateral circulation from the intact left coronary artery. Doppler echocardiography 4 weeks post-infarction showed pseudo-normalization of the A/E ratio of peak mitral flow velocity in atrial systole (A) to peak mitral flow velocity in early diastole (E). Preload reduction by nitroglycerin increased the A wave. Ten months post-infarction, the patient was re-admitted due to congestive heart failure. The A/E ratio was unchanged, however the A wave no longer increased after the same dose of nitroglycerin. We have hypothesized that dehydration and/or the vigorous use of a nitrate, in the acute phase of myocardial infarction, masked an underlying restrictive cardiomyopathy which progressed in the 10 months post-infarction.