Van Gelder I C, Tuinenburg A E, Schoonderwoerd B S, Tieleman R G, Crijns H J
Department of Cardiology, University Hospital Groningen, The Netherlands.
Am J Cardiol. 1999 Nov 4;84(9A):147R-151R. doi: 10.1016/s0002-9149(99)00715-8.
Conversion of atrial flutter and atrial fibrillation (AF) can be achieved by either pharmacologic or direct-current (DC) electrical cardioversion. DC electrical cardioversion is more effective and restores sinus rhythm instantaneously; however, general anesthesia is necessary, which can cause severe complications. On the other hand, pharmacologic cardioversion is less effective. First, time to conversion is unpredictable and may be relatively long, especially with oral drug therapy. Also, the rate of conversion is lower and depends on duration of AF. In addition, safety is an important issue. Adverse drug reactions include bradycardia, paradoxical tachycardia due to enhanced atrioventricular conduction, ventricular proarrhythmia, and acute heart failure. In paroxysmal AF, drug therapy is usually aimed at an acute conversion. Class IA and IC drugs are more efficacious than the class III drugs sotalol, amiodarone, and ibutilide. By contrast, class III drugs are more effective for the conversion of atrial flutter. Acute conversion out-of-hospital ("pill in the pocket approach") should be done only if the drug used appeared effective and safe after a few in-hospital trials. In persistent AF, DC conversion is preferred because drugs are particularly ineffective if the arrhythmia has lasted >24-48 hours. The latter probably relates to electrical and anatomical remodeling of the atria during ongoing atrial fibrillation and flutter. Nevertheless, a wait-and-see approach using, for example, oral amiodarone may be adopted with late DC conversion if the drug fails to convert persistent AF. However, the consequences of remodeling seem to dictate an early conversion. In this respect, echocardiography-guided DC cardioversion may become increasingly important in AF. It will prevent treatment resistance and potentially reduces embolic complications. In a hybrid approach, antiarrhythmic drugs may be used to enhance DC conversion and prevent (sub)acute recurrences of AF. However, it may increase the defibrillation threshold, especially if class IC drugs are used. New treatment options such as automatic defibrillation (implantable atrioverter) are still investigational.
心房扑动和心房颤动（AF）的转复可通过药物或直流电（DC）电击复律来实现。DC电击复律更有效，能即刻恢复窦性心律；然而，需要全身麻醉，这可能会导致严重并发症。另一方面，药物复律效果较差。首先，转复时间不可预测，可能相对较长，尤其是口服药物治疗时。而且，转复率较低，且取决于房颤的持续时间。此外，安全性是一个重要问题。药物不良反应包括心动过缓、因房室传导增强导致的反常性心动过速、室性心律失常和急性心力衰竭。在阵发性房颤中，药物治疗通常旨在急性转复。IA类和IC类药物比III类药物索他洛尔、胺碘酮和伊布利特更有效。相比之下，III类药物对心房扑动的转复更有效。只有在少数住院试验后所用药物显示有效且安全的情况下，才应进行院外急性转复（“口袋里的药丸”方法）。在持续性房颤中，首选DC转复，因为如果心律失常持续时间>24 - 48小时，药物特别无效。后者可能与持续性心房颤动和扑动期间心房的电和解剖重构有关。然而，如果药物未能转复持续性房颤，可采用例如口服胺碘酮的观察等待方法，随后进行DC转复。然而，重构的后果似乎要求早期转复。在这方面，超声心动图引导下的DC复律在房颤中可能变得越来越重要。它将防止治疗抵抗并可能减少栓塞并发症。在一种联合方法中，抗心律失常药物可用于增强DC转复并预防房颤的（亚）急性复发。然而，这可能会增加除颤阈值，尤其是使用IC类药物时。诸如自动除颤（植入式心房除颤器）等新的治疗选择仍在研究中。
