[Effects of nicardipine on left ventricular hypertrophy of the rat with renovascular arterial hypertension].

This study investigate the effects of Nicardipine treatment on regression of left ventricular hypertrophy (LVH), coronary hemodynamic and myocardial mechanical performance. 30 Sprague-Dawley male rats were divided into 3 groups: sham operated rats control group (SHC), untreated hypertensive rats group (RHR-U), treated hypertensive rats group (RHR-N). Systemic and coronary hemodynamics were determined by using left atrial injection of radioactive microspheres, 16 weeks after clipping. Mechanical performance was measured on isolated papillary muscle from the same animal. Results (mean +/- SEM) (Table: see text). Nicardipine treatment (10 to 15 mg intraperitoneal dosage during 8 weeks), led to: an efficient but incomplete control of hypertension. a reduction of left ventricular mass in proportion lesser than pressure decrease. a raise of coronary blood flow at rest with inversion of flow distribution between endocardium an epicardium. a decrease of "maximal" coronary blood flow. a reversal of impaired myocardial mechanical parameters towards control values except for contraction timing parameters. Decrease of "maximal" coronary blood flow could have deleterious effects on cardiac function.