Barold S Serge, Herweg Bengt
Department of Medicine, University of Rochester University School of Medicine and Dentistry, Rochester, NY, United States.
Department of Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, United States.
Front Cardiovasc Med. 2024 Aug 29;11:1450705. doi: 10.3389/fcvm.2024.1450705. eCollection 2024.
Mobitz type II second-degree atrioventricular block (AVB) is an electrocardiographic pattern that describes what appears to be an all-or-none conduction without visible changes in the AV conduction time or PR intervals before and after a single non-conducted wave. An unchanged PR interval after the block is a sine qua non of Mobitz type II block. A 2:1 AVB cannot be classified in terms of type I or type II AVB. The diagnosis of Mobitz type II block AVB requires a stable sinus rate, which is an important criterion because a vagal surge (generally benign) can cause simultaneous sinus slowing and AV nodal block, which can resemble Mobitz type II AVB. Atypical forms of Wenckebach AVB may be misinterpreted as Mobitz type II AVB when a series of PR intervals are constant before the block. Concealed His bundle or ventricular extrasystoles may mimic both Wenckebach and/or type II AVB (pseudo-AVB). Correctly identified Mobitz type II AVB is invariably at the level of the His-Purkinje system and is an indication for a pacemaker.
莫氏Ⅱ型二度房室传导阻滞（AVB）是一种心电图模式，描述的是在单个未下传的波之前和之后，房室传导时间或PR间期没有明显变化的情况下，似乎存在全或无传导。阻滞发生后PR间期不变是莫氏Ⅱ型阻滞的必要条件。2:1房室传导阻滞不能按照Ⅰ型或Ⅱ型房室传导阻滞进行分类。莫氏Ⅱ型房室传导阻滞的诊断需要窦性心律稳定，这是一个重要标准，因为迷走神经冲动（通常为良性）可导致窦性心动过缓和房室结阻滞同时出现，这可能类似于莫氏Ⅱ型房室传导阻滞。当一系列PR间期在阻滞前保持恒定时，不典型的文氏房室传导阻滞形式可能被误诊为莫氏Ⅱ型房室传导阻滞。隐匿性希氏束或室性期前收缩可能同时模拟文氏和/或Ⅱ型房室传导阻滞（假性房室传导阻滞）。正确识别的莫氏Ⅱ型房室传导阻滞总是发生在希氏-浦肯野系统水平，是植入起搏器的指征。
