Rest and Effort Hemodynamic Responses During Prolonged Treatment With Felodipine, 24-h Blood Pressure Monitoring, and Echocardiographic Changes

In an open study, 16 patients with moderate essential hypertension were treated with 5 or 10 mg felodipine daily for 3 months. Hemodynamic (HD) indices were assessed at rest and during isometric effort (IE) at days 0, 3 to 7, 30, 60, and 90. Treatment efficacy was evaluated by ambulatory blood pressure monitoring for (ABPM) 24 h and divided between awake and sleep periods. Left ventricular mass (LVM) was determined before and at the end of treatment. Treatment normalized blood pressure (BP) in all patients (5 mg in 7 and 10 mg in 9). Systolic diastolic and mean arterial pressure (MAP) decreased significantly during the study (P< .01). The decrease in BP was significant on day 3 to 7 (P<.01) and tended to decrease further with treatment. Resting heart rate (HR) did not change. After 3 months systolic and diastolic pressureand MAP decreased significantly. Mean HR during ABPM differed between awake and sleep hours but did not change with treatment. When ABPM was divided into daytime and nighttime the awake BP decreased after 3 months (P< .01), but sleep measurements showed only a borderline decrease (P = .05). MAP after 3 months decreased in both awake and sleep periods. LV maximal and minimal dimensions did not change during treatment. Interventricular septum, posterior wall thickness, LVM, LVM/body surface area, and LVM/height tended to decrease, however this change was not significant. Hemodynamic measurements were measured at rest, at peak IE and posteffort. During treatment rest systemic vascular resistance (SVR) and MAP decreased, and there was no difference in ventricular ejection time, HR, and cardiac index. The increase in BP at IE was not prevented by treatment. After effort MAP decreased significantly and SVR tended to decrease in treated patients. Felodipine normalized resting BP in all patients. The main antihypertensive effect came at daytime and was less during sleep. No reflex tachycardia was seen during treatment. Echocardiographic measurements showed preservation of systolic and diastolic function and a tendency of decrease in LVM. Probably longer period of treatment is needed for clear-cut regression of LVM. Felodipine did not prevent the increase in BP and SVR during isometric effort, implying that normal cardiovascular reflexes are preserved during treatment.