Bardy G H, Sawyer P L, Johnson G W, Ivey T D, Reichenbach D D
Department of Medicine, University of Washington, Seattle 98195.
Am J Physiol. 1989 Nov;257(5 Pt 2):H1534-42. doi: 10.1152/ajpheart.1989.257.5.H1534.
Multiple paired lesions produced by a train of high-voltage low-charge rectangular pulses (20 A, 30 microsecond) and a train of low-voltage high-charge rectangular pulses (2 A, 300 microsecond) were made to the left ventricular epicardium of 23 dogs to determine the relative influence of voltage and charge delivery on injury of canine myocardium. Both pulsing methods contained equal amounts of energy (15 J) delivered over equal periods of time (100 ms), and both pulsing methods were nonarcing and therefore nonbarotraumatic. The volume of cardiac tissue injury resulting from both types of pulses was then evaluated from planimetered serial histological sections after 1, 10, and 30 days. Over the 30-day period, lesion size progressively decreased to 56% of its original value for the high-voltage low-charge pulse. In contrast, lesion size from the low-voltage high-charge pulse remained relatively constant, decreasing only 12% of its original value. These results indicate that when energy delivery is held constant, voltage, not charge, is the dominant mediator of cell injury. Also, cells subjected to high voltages appear to recover partially over time with significantly less constancy of tissue injury than that seen with low-voltage high-charge pulses.
对23只犬的左心室心外膜施加一系列高压低电荷矩形脉冲（20 A，30微秒）和一系列低压高电荷矩形脉冲（2 A，300微秒）产生多个配对损伤，以确定电压和电荷传递对犬心肌损伤的相对影响。两种脉冲方法在相同时间（100毫秒）内传递的能量相等（15焦耳），且两种脉冲方法均不产生电弧，因此无气压伤。然后在1天、10天和30天后，通过对连续组织学切片进行面积测量来评估两种类型脉冲导致的心脏组织损伤体积。在30天的时间里，高压低电荷脉冲导致的损伤大小逐渐减小至其原始值的56%。相比之下，低压高电荷脉冲导致的损伤大小保持相对恒定，仅减小至其原始值的12%。这些结果表明，当能量传递保持恒定时，电压而非电荷是细胞损伤的主要介质。此外，受到高电压作用的细胞似乎会随着时间的推移部分恢复，与低压高电荷脉冲相比，组织损伤的稳定性明显更低。
