Left ventricular changes after chronic therapy with enalapril maleate in moderate to severe hypertensive patients

A randomized double-blind trial was carried out to determine the relationship of the changes in blood pressure and heart rate with changes in echocardiographic left ventricular indices in moderate to severe hypertensive patients with established left ventricular hypertrophy who were being treated chronically with enalapril or hydrochlorothiazide plus propranolol for 26 weeks. After a 2-week period on placebo, drug dosages in the two groups were adjusted to individual needs until blood pressure was normalized (diastolic less than 90 mmHg). Patients in Group I received 10 to 40 mg enalapril/day; those in Group II received 50 mg hydrochlorothiazide plus 80 to 240 mg propranolol/day. Echocardiographic measurements were made at the end of the placebo and 26-week active treatment periods. Significant correlations were observed between the changes in four pairs of variables in each group. In the 8 patients receiving enalapril, there were negative correlations between interventricular septal thickness and supine systolic blood pressure, erect and supine heart rates, and a positive correlation between relative wall thickness and erect diastolic blood pressure. In the 7 patients on hydrochlorothiazide plus propranolol, there were negative correlations between relative wall thickness and erect and supine heart rate, and positive correlations between left ventricular mass and erect diastolic blood pressure, and the percentage change in internal diameter of the left ventricle and supine systolic blood pressure. Possible explanations for and implications of these regional changes are discussed.