PRESERVED VENTRICULAR PUMP FUNCTION AFTER A MARKED REDUCTION OF LEFT-VENTRICULAR MASS

Objectives. This study was designed to evaluate the long-term effects of combination therapy with an angiotensin-converting enzyme inhibitor and a beta-adrenergic blocking agent on the relation between the decrease in arterial pressure at rest and during exercise and the decrease in left ventricular mass. Background. A variety of antihypertensive drugs including angiotensin-converting enzyme inhibitors and beta-blockers have been shown to reduce ventricular hypertrophy, although little is known about combination therapy and the time course of such a reduction. Methods. Twenty-one patients with previously untreated essential hypertension were treated with a low dose combination of 50 mg of atenolol and 10 mg of enalapril once daily for 39 months. Cardiovascular findings were assessed by two-dimensionally guided M-mode echocardiography in the pretreatment phase and after 6 and 39 months of combination therapy. Results. Combination therapy reduced arterial pressure at rest from 161/108 to 130/86 mm Hg (p < 0.001) and exercise arterial pressure at 100 W from 192/112 to 167/95 mm Hg (p < 0.001). After 6 months of treatment, significant decreases in interventricular septal thickness (9%, p < 0.001), posterior wall thickness (9%, p < 0.001) and left ventricular mass index (16%, p < 0.001) were demonstrated on the echocardiogram. After 39 months of therapy, reductions in these values were 28% (p < 0.001), 29% (p < 0.001) and 40% (p < 0.001), respectively. Conclusions. Long-term treatment with combination therapy of atenolol and enalapril produced significant reductions in arterial pressure at rest and during exercise accompanied by a marked reduction of left ventricular mass. However, whereas arterial pressure decreased immediately and remained unchanged, left ventricular mass decreased more gradually and continued to decrease throughout the treatment period of >3 years. Despite this marked reduction in left ventricular mass, left ventricular pump function was well preserved during rest and exercise.