Biventricular endomyocardial biopsy findings in essential hypertension of graded severity

We performed endomyocardial biopsies from both ventricles in 29 patients with graded severities of hypertension. The patients (53.8 +/- 8.1 (mean +/- s.d.) years old) were either symptomatic or asymptomatic, and were grouped into three grades according to the severity of hypertension, that is, slight, moderate and severe. Breadth of the left ventricular myocytes (expressed as mean +/- s.d. microns) were 14.6 +/- 2.0 in Group I (n = 5), 15.5 +/- 1.4 in Group II (n = 15) and 18.7 +/- 2.4 in Group III (n = 9) showing a gradual increase. A noteworthy increase in the right ventricular myocyte breadth was also observed (12.5 +/- 0.9 microns in Group I, 13.6 +/- 1.7 microns in Group II and 14.7 +/- 1.4 microns in Group III, respectively). Increase in the interstitial fibrosis which was determined by the point counting method and expressed in percentage was also observed in both ventricular myocardiium (14.2 +/- 2.4 microns in Group I, 15.7 +/- 1.8 microns in Group II, and 16.2 +/- 3.1 microns in Group III in the left ventricle and 12.7 +/- 2.4 microns in Group I, 14.6 +/- 2.7 microns in Group II, and 17.5 +/- 3.5 microns in Group III in the right ventricle). It is concluded that, in the hypertensive heart, increase in the breadth of the myocytes as well as the interstitial fibrosis occurs in both the left and the right ventricle, and both changes progress in accordance with the severity of hypertension and electrocardiographic abnormalities.