The role of the autonomic nervous system in the action of verapamil on the sinus node in man

摘要: To elucidate the role of autonomic nervous system in modulating effect verapamil on sinus node (SN) function, five volunteers were repeatedly studied both with and without prior blockade. Verapamil alone (0.1 mg/kg i.v.) caused a significant decrease spontaneous cycle length (SCL) from 1104±111.6 msec to 891±67 (mean ±S.D., P<0.01). After pretreatment propranolol atropine (0.02 i.v.), had an opposite SCL increase 686±66 (pre) plateau alternating between 690 712 (post) (P<0.01). Pretreatment did not prevent after injection verapamil; changed 1295±85 1020±87 The extent this was similar any pretreatment. pretreatment, there small but insignificant during first minutes; whereas later increased. led fall blood pressure. no change pressure either or results suggest that plays important part SN function man. cardio-accelerating is provoked by consecutive restraint vagal innervation direct vagolytic action drug. An sympathetic tone seems be less important.