Cardiac hypertrophy in idiopathic dilated congestive cardiomyopathy: a clinicopathologic study.

Abstract

Although clinical studies indicate that patients with idiopathic dilated congestive cardiomyopathy who develop ECG or angiographic signs of left ventricular (LV) hypertrophy may survive longer, there is little morphologic evidence for such anatomic favorable or unfavorable prognostic groups. Autopsied patients (30) who died of dilated cardiomyopathy were studied; 15 died within 1 yr of the 1st symptom of their disease (short-term survivors) and 15 patients died 1-14 yr after initial symptoms (long-term survivors). There were no significant differences in sex, race, clinical presentation or cause of death between the groups, but there were significant morphologic differences. In the short-term survivors, average heart weight was 540 g and LV wall thickness was 1.0 cm; in the long-term survivors, the average heart weight was 759 g and LV wall thickness was 1.3 cm (P < 0.001). LV cavity dilatation as measured by maximal transverse diameter from the postmortem angiograms did not differ between the 2 groups. These patients were compared with 10 autopsied patients with normal hearts and no clinical cardiac disease and 10 autopsied patients with volume overload secondary to valvular regurgitation. An LV hypertrophy/dilatation index (thickness/diameter) was 0.17 .+-. 0.07 for the short-term survivors, 0.21 .+-. 0.07 for the long-term survivors, 0.38 .+-. 0.07 for volume overload patients and 0.48 .+-. 0.19 for normal subjects (F = 20.24, P < 0.001). In patients with hypertrophy due to volume overload, wall thickening increased with dilatation, returning the ratio of wall thickness to cavity size toward normal. Among the idopathic congestive cardiomyopathies, dilatation was disproportionate to hypertrophy and the difference was most marked for short-term survivors.