The effects of amlodpine (300 μg/kg administered intravenously), a new, long-acting, dhydropyridne class, calcium channel blocking drug, were studied in atrially paced (120 beats/min), autonomicaly blocked dogs. Hemodynmnic and electrophysiologic parameters were measured before and up to 3 hours after amlodpine. Coronary blood flow was significantly increased 10 and 30 minutes after drug administration, whereas cardiac output and mean arterial pressure were unaffected. Coronary vascular resistance was decreased but total systemic vascular resistance did not change. Atrioventricular (AV) nodal conduction was slightly prolonged, as reflected by increases in strial-His bundle and AV conduction times and PR interval, 30 minutes after administration. AN parameters returned toward their control values within 3 hours after drug administration. Comparison of coronary vascular resistance and AV conduction changes with those previously reported for other calcium channel blocking drugs where autonomic blockade existed suggests that at equivalent levels of coronary vasodilation, amlodipine's effects more closely resemble the effects of ditiazem or verapamil than other dihydropyrtdines.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine