Tacker W A, Davis J S, Lie J T, Titus J L, Geddes L A
Med Instrum. 1978 Jan-Feb;12(1):27-30.
High-energy transchest damped wave sine defibrillation shocks have been shown to produce cardiac damage when applied in rapid sequence. However, there are no reports as to whether single, threshold-intensity shocks produce damage. In this study, nonfibrillating dogs were subjected either to a single, threshold-intensity (1 A/kg) shock, or to a series of 6 shocks with high intensity (3 to 4.8 A/kg). Electrodes of 8 cm diameter were used to apply the shock through the chest wall. Dogs receiving shocks of adequate (but not excessive) strength to defibrillate showed no cardiac damage, although they exhibited transient ventricular arrhythmias after the shock was applied. All dogs receiving the higher intensity, multiple shocks showed gross and microscopic evidence of cardiac damage. Ventricular lesions were observed in both right and left ventricular free walls and were sometimes transmural in extent. ECG analysis of the records from the dogs receiving multiple, high-intensity shocks showed second and third degree A-V block, ventricular ectopic beats, ventricular tachycardia, S-T segment changes, and T-wave inversion. Although multiple, high-energy, high-current defibrillation shocks produce permanent cardiac damage in dogs, threshold shocks do not produce morphologic changes.
高能量经胸阻尼正弦波除颤电击在快速连续应用时已被证明会导致心脏损伤。然而，关于单次阈强度电击是否会造成损伤尚无相关报道。在本研究中，非颤动状态的犬只接受单次阈强度（1 A/kg）电击，或一系列6次高强度（3至4.8 A/kg）电击。使用直径8厘米的电极通过胸壁施加电击。接受足以除颤（但不过量）强度电击的犬只未显示心脏损伤，尽管在施加电击后出现了短暂的室性心律失常。所有接受更高强度多次电击的犬只均显示出心脏损伤的大体和微观证据。在左右心室游离壁均观察到心室病变，且有时病变会累及全层。对接受多次高强度电击犬只的记录进行心电图分析显示有二度和三度房室传导阻滞、室性早搏、室性心动过速、ST段改变以及T波倒置。虽然多次高能量、高电流除颤电击会对犬只造成永久性心脏损伤，但阈强度电击不会产生形态学改变。
