Czarnecki W, Herbaczyńska-Cedro K
Int J Clin Pharmacol Ther Toxicol. 1980 Apr;18(4):145-9.
Increased activity of sympathetic nervous system enhances cardiac susceptibility to arrhythmias. Clonidine through its central action decrease sympathetic activity to the heart. The aim of this study was to investigate whether Clonidine influences excitability and refractoriness of the heart in such a way that cardiac susceptibility to arrhythmias is reduced. The effect of Clonidine (5 microgram/kg i.v.) on diastolic threshold and refractory period was investigated in the normal cat heart in situ paced at a constant rate. Clonidine increased diastolic threshold up to 63.5 +/- 24.0% (mean +/- SE) of initial value and prolonged refractory period up to 13.2 +/- 2.4% of the control throughout 120 min of observation. These data suggest that Clonidine might be of value as an antiarrhythmic agent in patients with chronic angina in whom ventricular arrhythmias are often associated with excessive sympathetic activity.
交感神经系统活性增加会增强心脏对心律失常的易感性。可乐定通过其中枢作用降低心脏的交感神经活性。本研究的目的是调查可乐定是否以降低心脏对心律失常易感性的方式影响心脏的兴奋性和不应期。在原位以恒定速率起搏的正常猫心脏中，研究了可乐定（5微克/千克静脉注射）对舒张期阈值和不应期的影响。在整个120分钟的观察期内，可乐定使舒张期阈值提高至初始值的63.5±24.0%（平均值±标准误），并使不应期延长至对照值的13.2±2.4%。这些数据表明，对于慢性心绞痛患者，可乐定作为一种抗心律失常药物可能具有价值，这类患者的室性心律失常常与交感神经活动过度有关。
