[Numbers and sizes of myocytes, amount of interstitial space, fibrosis and disarray in dilated cardiomyopathy].

The features characteristic of dilated cardiomyopathy (DCM) are dilatation of the left ventricular cavity without thickening of the wall, and decreased contractility of the left ventricle. The myocardial wall thickness depends on three variables: the number of muscle layers, the mean size of myocytes and the percent area of interstitial space. To clarify the histological pathogenesis of the special features of DCM, these three variables including wall thickness, fibrosis and disarray in the left ventricular wall of autopsied hearts were quantitatively measured in 10 patients with DCM, 10 patients with hypertrophic cardiomyopathy (HCM) and 20 patients with normal hearts (N). The heart weight was 651 +/- 128 g in the DCM group, 614 +/- 216 g in the HCM group, and 280 +/- 40 g in N group. The S (ventricular septum)/F (left ventricular free wall) of the wall thickness was 9 +/- 1/9 +/- 1 (mm) in DCM, 25 +/- 5/16 +/- 2 (mm) in HCM, and 13 +/- 1/13 +/- 1 (mm) in the N group. The S/F of % fibrosis was 9 +/- 5/11 +/- 4 in DCM, 14 +/- 4/8 +/- 5 in HCM, and 1 +/- 1/1 +/- 1 in N. S/F of the size (mu) of myocytes was 18 +/- 2/21 +/- 3 in DCM, 19 +/- 3/21 +/- 2 in HCM, and 13 +/- 1/14 +/- 1 in N. S/F of the numbers of muscle layers was 310 +/- 60/260 +/- 40 in DCM, 630 +/- 80/360 +/- 70 in HCM.(ABSTRACT TRUNCATED AT 250 WORDS)