Colatsky T J, Follmer C H, Starmer C F
Division of Experimental Therapeutics, Wyeth-Ayerst Research, Princeton, New Jersey 08543.
Circulation. 1990 Dec;82(6):2235-42. doi: 10.1161/01.cir.82.6.2235.
Although work on class III antiarrhythmics remains at an early stage, these agents still appear to possess greater efficacy and less proarrhythmia than conventional class I agents in those experimental arrhythmia models considered to be most representative of the clinical situation. Although prolongation of repolarization carries with its own tendency for pause-dependent arrhythmogenesis (i.e., torsade de pointes), available data suggest that this may be a function of nonspecificity in potassium channel block rather than a general characteristic of class III activity. The availability of new and more selective blockers of specific cardiac potassium channels under development as class III agents have already helped to clarify basic questions about the ionic mechanism of repolarization in the heart, and one hopes that a growing clinical data base will eventually determine the relative safety and efficacy of these agents in preventing symptomatic and life-threatening arrhythmias.
尽管III类抗心律失常药物的研究仍处于早期阶段，但在那些被认为最能代表临床情况的实验性心律失常模型中，这些药物似乎比传统的I类药物具有更高的疗效和更低的促心律失常作用。尽管复极延长本身就有发生依赖于长间歇的心律失常（即尖端扭转型室速）的倾向，但现有数据表明，这可能是钾通道阻滞非特异性的作用，而非III类活性的普遍特征。作为III类药物正在研发的新型且更具选择性的特异性心脏钾通道阻滞剂，已经有助于阐明有关心脏复极离子机制的基本问题，人们希望不断增加的临床数据库最终能确定这些药物在预防有症状的和危及生命的心律失常方面的相对安全性和疗效。
