Abstract
We used spectral analysis of heart rate variability (HRV) to study the effects of calcium channel blockers diltiazem and nicardipine on the sympathetic nervous activity.
Energy in the low-frequency range (0.04 to 0.12Hz) in supine position was used as a quantitative index of sympathetic nervous activity.
Ten male patients were studied. Four patients were received diltiazem 10mg ; six patients were received nicardipine 0.5mg. HRV and arterial blood pressure were recorded 10 min before injection and 10 min after injection.
The systolic blood pressure and diastolic blood pressure were both reduced after injection of either drugs. Diltiazem significantly reduced low-frequency range, but nicardipine revealed no obvious changes. There results suggest that diltiazem may reduce sympathetic nervous activity.
