Santini M, Pandozi C, Gentilucci G, Villani M, Scianaro M C
Department of Cardiology, S. Filippo Neri Hospital, Rome, Italy.
J Cardiovasc Electrophysiol. 1998 Aug;9(8 Suppl):S170-6.
Low-energy intra-atrial defibrillation is a new therapeutic option for restoring sinus rhythm in patients with atrial fibrillation (AF). The success rate is quite high when right atrium-coronary sinus or right atrium-pulmonary artery electrode configurations are used, although the former is associated with a slightly lower defibrillation threshold. Several issues regarding the safety and tolerability of the procedure remain unresolved. Our experience and that of others indicate that low-energy intra-atrial cardioversion is safe even during exercise, provided the shock is well synchronized with the QRS and the preshock RR interval is > 500 msec. Reported defibrillation thresholds in patients with persistent AF range from 4 to 8 J, and shocks of this type inevitably are associated with some degree of discomfort. Measures aimed at lowering the defibrillation threshold (e.g., use of biphasic waveforms, antiarrhythmic pretreatment, and use of a single effective shock, as opposed to the multiple shocks delivered in research settings) can be expected to increase patient tolerance and extend the indications for low-energy intra-atrial cardioversion. The procedure currently is indicated for patients with persistent AF who are resistant to external defibrillation unable or unwilling to undergo general anesthesia. The procedure could be expanded to patients affected by obesity in whom the efficacy of external cardioversion is lower.
低能量心房内除颤是恢复心房颤动（AF）患者窦性心律的一种新的治疗选择。当采用右心房-冠状窦或右心房-肺动脉电极配置时，成功率相当高，尽管前者的除颤阈值略低。关于该手术安全性和耐受性的几个问题仍未解决。我们和其他人的经验表明，只要电击与QRS波良好同步且电击前RR间期>500毫秒，即使在运动期间低能量心房内心脏复律也是安全的。持续性AF患者报告的除颤阈值为4至8焦耳，这种类型的电击不可避免地会带来一定程度的不适。旨在降低除颤阈值的措施（例如，使用双相波形、抗心律失常预处理以及使用单次有效电击，而不是研究环境中给予的多次电击）有望提高患者耐受性并扩大低能量心房内心脏复律的适应症。该手术目前适用于对体外除颤有抵抗、无法或不愿接受全身麻醉的持续性AF患者。该手术可扩大到体外心脏复律效果较差的肥胖患者。
