Abstract 16502: Effect of Azelnidipine, an Unique Calcium Channel Blocker, and Amlodipine on Sympathetic Nerve Activity in Primary Hypertensive Patient
Purpose: Calcium channel blocker is one of antihypertensive drugs that have strong vasodilatation.However, baroreflex mediated sympathetic activationmight cause adverse effects in hypertensive patients.A recent develpoed unique calcium channel blocker, azelnidipine, is known to decrease heart rate while it lowers blood pressure as a vasodilator. It has been suggested the possibility that azelnidipine inhibits sympathetic nerve activity to decrease heart rate. In this study, we evaluated whether azelnidipine has inhibitory effects on sympathetic nerve activity compared to amlodipine in primary hypertensive patient.
Method: Prospective, open-label, randomized, and cross-over design was applied in this study. Hypertensive patients who had not been under good control(>140/90mmHg) were recruited. The patient was excluded if he had taken calcium channel blocker or beta blocker. 10 patients(62.9±11.1y.o.) were enrolled, and each patient was measured blood pressure, heart rate, and muscle sympathetic nerve activity(MSNA) after the medication with each calcium channel blocker for 8weeks.
Result: Before taking amlodipine or azelnidipine, the average blood pressure of the patients was 153.2±7.6/90.7±5.6mmHg, and the average heart rate was 71.3±11.4beats /min. Systolic and diastolic pressure of the patients after taking each drug decreased significantly. No significant difference was observed in systolic blood pressure(129.0±10.8v.s.123.8±10.6mmHg, p>0.05) between two groups. However, heart rate of the patients in azelnidipine group decreased significantly(64.9±8.8beats/min, p<0.05). The average of MSNA was 48.5±10.1bursts/100min in baseline. MSNA did not change significantly in both groups compared to baseline. However there was a significant difference in MSNA between amlodipine group and azelnidipine group(60.1±9.7 v.s. 47.8±16.6bursts/100beats, p<0.05).
Conclusion: Our study indicates that azelnidipine, which is different from amlodipine, may decrease heart rate by inhibiting sympathetic nerve activity in hypertensive patients.
- Autonomic nervous system
- Calcium channel blockers
- Vasodilator agents
- Heart rate/Heart rate variability
- © 2013 by American Heart Association, Inc.