Landymore R W, Marble A E, Cameron C A
Ann Thorac Surg. 1986 Apr;41(4):372-7. doi: 10.1016/s0003-4975(10)62689-6.
Recent reports have suggested that small-amplitude electrical activity may persist following the administration of potassium cardioplegia. This report confirms the presence of small-amplitude electrical activity in the potassium-arrested heart and describes a canine model that may be used to measure microvolt plunge-electrode potentials during ischemic arrest. Thirty-one adult mongrel dogs were placed on cardiopulmonary bypass and underwent 90 minutes of ischemic arrest. The heart was arrested with 10 ml per kilogram of body weight of crystalloid cardioplegia (20 mEq of KCl/L) at 4 degrees C. Core temperature was maintained at 26 degrees C and myocardial temperature, within a range of 8 degrees to 10 degrees C with topical ice-slush saline solution. Cardioplegic solution, 10 ml/kg, was reinfused every 30 minutes during the 90 minutes of ischemia. Electrical activity and transmural temperature were continuously monitored over the anterior surface of the left ventricle with specially designed plunge electrodes. Visual electrical and mechanical activity ceased in each animal after the infusion of cardioplegic solution, and was associated with an isoelectric electrocardiogram. However, microvolt (10(-6)V) small-amplitude electrical activity was recorded at a myocardial temperature of 10 degrees C in each animal during ischemic arrest, and the activity from 6 animals was stored on magnetic tape. Spectral analysis of electrical activity during cardioplegic arrest indicated that the fundamental frequency of small-amplitude electrical activity was in the range of 3.25 Hz. These data confirm the presence of small-amplitude electrical activity in the cardioplegia-arrested heart at 10 degrees C.
最近的报告表明，在给予钾停搏液后，可能会持续存在小幅度电活动。本报告证实了钾停搏心脏中存在小幅度电活动，并描述了一种犬类模型，可用于测量缺血停搏期间的微伏插入电极电位。31只成年杂种犬接受体外循环，并经历90分钟的缺血停搏。心脏在4℃时用每千克体重10ml的晶体停搏液（20mEq KCl/L）停搏。核心温度维持在26℃，心肌温度通过局部冰盐水溶液维持在8℃至10℃范围内。在90分钟的缺血期间，每30分钟再输注10ml/kg的停搏液。用专门设计的插入电极连续监测左心室前表面的电活动和透壁温度。在每只动物输注停搏液后，可见的电活动和机械活动停止，并伴有心电图等电位线。然而，在缺血停搏期间，每只动物在心肌温度为10℃时记录到微伏（10^(-6)V）小幅度电活动，6只动物的活动记录在磁带上。停搏期间电活动的频谱分析表明，小幅度电活动的基频在3.25Hz范围内。这些数据证实了在10℃的停搏心脏中存在小幅度电活动。
