Cleland John G F, Nasir Mansour, Tageldien Ahmed
Department of Cardiology, Castle Hill Hospital, University of Hull, Kingston upon Hull HU16 5TX, UK.
Nat Clin Pract Cardiovasc Med. 2007 Feb;4(2):90-101. doi: 10.1038/ncpcardio0794.
Reduced cardiac efficiency caused by suboptimal synchronization of the heart's normal contraction might contribute to the development of or exacerbate heart failure. Conceptually and in practice cardiac dyssynchrony is complex. Recent studies have shown that atrio-biventricular pacing can improve cardiac synchrony in many patients and improve cardiac function, symptoms and exercise capacity, and reduce morbidity and mortality substantially. Randomized controlled trials, however, indicate that the severity of cardiac dyssynchrony, as conventionally measured, is a poor guide to treatment benefit and that correction of dyssynchrony accounts for only part of the benefit of atrio-biventricular pacing. Although some of the benefits of atrio-biventricular pacing might be mediated by cardiac resynchronization, much of the benefit could be mediated by mechanisms that are as yet unknown. Withholding atrio-biventricular pacing in patients who do not exhibit cardiac dyssynchrony on imaging but otherwise fulfil the entry criteria used in randomized controlled trials of this therapy could be unwise. Here, we examine the evidence that cardiac resynchronization is indeed the mechanism by which atrio-biventricular pacing exerts its effects.
心脏正常收缩的同步性欠佳导致心脏效率降低，这可能会促使心力衰竭的发生或使其恶化。从概念和实际情况来看，心脏不同步是复杂的。最近的研究表明，房室双腔起搏可以改善许多患者的心脏同步性，并改善心脏功能、症状和运动能力，还能大幅降低发病率和死亡率。然而，随机对照试验表明，按照传统方法测量的心脏不同步严重程度并不能很好地指导治疗获益情况，而且纠正不同步仅占房室双腔起搏获益的一部分。虽然房室双腔起搏的一些益处可能是由心脏再同步化介导的，但许多益处可能是由尚不清楚的机制介导的。对于那些在影像学上未表现出心脏不同步但在其他方面符合该疗法随机对照试验纳入标准的患者，不进行房室双腔起搏可能是不明智的。在此，我们审视了心脏再同步化确实是房室双腔起搏发挥作用的机制的证据。
