Ikeno S, Akazawa S, Shimizu R, Nakaigawa Y, Ishii R, Inoue S, Satoh M
Department of Anaesthesiology, Jichi Medical School, Tochigi, Japan.
Can J Anaesth. 1999 Feb;46(2):148-53. doi: 10.1007/BF03012549.
To determine the effects of propofol on the cardiac conduction system in dogs with pharmacological autonomic blockade.
In eight mongrel dogs receiving 6 mg.kg-1.hr-1 propofol and vecuronium under pharmacological autonomic blockade with atropine and propranolol the infusion rates of propofol were increased from 6, (baseline), to 12, 18 and 24 mg.kg-1.hr-1 at 60-min intervals. An electrophysiological study assessed sinus rate, sinus node recovery time, corrected sinus node recovery time, intraatrial conduction time, AV nodal effective refractory period, Wenckebach cycle length and AV conduction times. Electrocardiographical variables and arterial pressures were also measured. All measurements were repeated at 30 min after the beginning of each infusion of propofol.
Propofol did not produce direct effects on the electrophysiological or electrocardiographical variables at any infusion rates. Heart rates did not change at higher infusion rates in the presence of decreases in arterial pressures.
Propofol did not affect the cardiac conduction system in the presence of autonomic blockade. Thus, the direct cardiac effects of propofol do not play a causative role in the genesis of propofol-associated bradyarrhythmias.
确定丙泊酚对药理学自主神经阻滞犬心脏传导系统的影响。
在8只杂种犬中，在阿托品和普萘洛尔进行药理学自主神经阻滞后，给予6mg·kg-1·hr-1丙泊酚和维库溴铵，丙泊酚输注速率每隔60分钟从6mg·kg-1·hr-1（基线）增加到12、18和24mg·kg-1·hr-1。进行电生理研究以评估窦性心率、窦房结恢复时间、校正窦房结恢复时间、心房内传导时间、房室结有效不应期、文氏周期长度和房室传导时间。还测量心电图变量和动脉压。在每次输注丙泊酚开始后30分钟重复所有测量。
在任何输注速率下，丙泊酚对电生理或心电图变量均未产生直接影响。在动脉压降低的情况下，较高输注速率时心率未改变。
在自主神经阻滞存在的情况下，丙泊酚不影响心脏传导系统。因此，丙泊酚的直接心脏作用在丙泊酚相关性缓慢性心律失常的发生中不起因果作用。
