New York Harbor Veterans Administration Healthcare System, Brooklyn, NY 11209, USA.
Heart Rhythm. 2009 Oct;6(10):1514-21. doi: 10.1016/j.hrthm.2009.06.025. Epub 2009 Jun 21.
The era of deductive analysis of the electrocardiogram was prolific in its ability to yield accurate inferences regarding the pathophysiology of a vast number of heart rhythm disorders. However, occasionally there was a tendency to infer hypothetical electrophysiological mechanisms without the benefit of direct cellular information. This turned out to be misleading in some cases in which suggested mechanisms were subsequently found to be incorrect, and it also unintentionally hampered the search for more basic mechanisms. Two cases in point are the use of the terms “phase 3” and “phase 4” block in reference to tachycardia-dependent (TD) and pause-dependent (PD) paroxysmal atrioventricular block (PAVB), respectively. Not only did basic studies definitely show that TD-PAVB is not related to phase 3 block, but also significant basic studies demonstrated that PD-PAVB need not depend on a phase 4 depolarization mechanism. Here we revisit the problems of TD- and PD-PAVB and illustrate by clinical and basic science examples possible pathophysiological mechanisms.
心电图演绎分析的时代硕果累累，能够对大量心律失常的病理生理学做出准确推断。然而，有时在没有直接细胞信息的情况下，人们倾向于推断假设的电生理机制。在某些情况下，这被证明是具有误导性的，因为后来发现所提出的机制是不正确的，而且它也无意中阻碍了对更基本机制的探索。有两个例子可以说明这一点，即分别用“相 3”和“相 4”阻滞来指代心动过速依赖性（TD）和停搏依赖性（PD）阵发性房室传导阻滞（PAVB）。基础研究不仅明确表明 TD-PAVB 与相 3 阻滞无关，而且重要的基础研究还表明 PD-PAVB 不一定依赖于相 4 去极化机制。在这里，我们重新探讨 TD-PAVB 和 PD-PAVB 的问题，并通过临床和基础科学的例子来说明可能的病理生理学机制。
