Acute inotropic effects of intravenous nifedipine and its vehicle compared with saline: a double-blind study of systolic time intervals in normal subjects.

1. The inotropic effects of intravenous nifedipine and its vehicle were studied noninvasively in a double-blind placebo controlled crossover fashion using systolic time intervals in 12 normal subjects. 2. Nifedipine caused vasodilation, a fall in systolic and diastolic blood pressure, and increased heart rate. The vehicle alone caused vasodilation and decreased systolic blood pressure, without a change in heart rate. 3. Nifedipine increased left ventricular ejection time (LVET) and decreased pre-ejection period (PEP) and the ratio PEP/LVET, whereas the vehicle alone had the opposite effect. Neither treatment affected the total duration of electromechanical systole. 4. These results suggest that the vehicle has a negative inotropic effect, which is overcome by the indirect positive inotropic effect of nifedipine when they are administered together systemically.

RCT Entities:   Population Interventions Outcomes