Nishihara Ami, Okabe Yuta, Morizumi Sei, Enomoto Yoshiharu, Yoshida Kentaro
Department of Cardiology, Ibaraki Prefectural Central Hospital, 6528 Koibuchi, Kasama 309-1793, Japan.
Department of Cardiology, Institute of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan.
Eur Heart J Case Rep. 2024 Oct 5;8(10):ytae549. doi: 10.1093/ehjcr/ytae549. eCollection 2024 Oct.
One of the most important and relatively frequent complications of aortic valve replacement is atrioventricular block. It typically occurs by direct injury of the infranodal conduction system due to intra-operative manipulation and persists post-operatively, necessitating permanent pacemaker implantation in many cases.
A 66-year-old man presented to our hospital after experiencing syncope while walking after drinking. He had experienced two episodes of alcohol-induced syncope several years earlier. His electrocardiogram (ECG) and transthoracic echocardiogram revealed complete atrioventricular block and severe aortic stenosis, respectively. He received a temporary pacemaker on the day of admission and underwent surgical aortic valve replacement on hospital Day 9. The native aortic valve was bicuspid. Unexpectedly, the ECG immediately after aortic valve replacement showed complete restoration of atrioventricular conduction during temporary atrial pacing. The atrioventricular block did not recur, and he was discharged to home on post-operative Day 13.
This remarkably rare clinical course, complete restoration from complete and persistent atrioventricular block after surgical aortic valve replacement, can be explained by multifactorial mechanisms: (i) surgical removal of the aortic annulus calcification directly hindering the infranodal conduction system; (ii) relief from the ventricular pressure overload stressing the conduction system within the septum; and (iii) improvement of substantial autonomic dysregulation as manifested by alcohol-sensitive syncope in the present patient, which was a result of unloading of the intraventricular pressure affecting the left ventricular mechanoreceptor.
主动脉瓣置换术最重要且相对常见的并发症之一是房室传导阻滞。它通常是由于术中操作导致结下传导系统直接受损而发生，并在术后持续存在，在许多情况下需要植入永久起搏器。
一名66岁男性在饮酒后行走时出现晕厥，随后到我院就诊。他在几年前曾经历过两次酒精诱发的晕厥。他的心电图（ECG）和经胸超声心动图分别显示完全性房室传导阻滞和严重主动脉瓣狭窄。他在入院当天接受了临时起搏器植入，并于住院第9天接受了主动脉瓣置换手术。原主动脉瓣为二叶式。出乎意料的是，主动脉瓣置换术后立即进行临时心房起搏时，心电图显示房室传导完全恢复。房室传导阻滞未复发，他于术后第13天出院回家。
这种极为罕见的临床过程，即主动脉瓣置换术后完全性且持续性房室传导阻滞完全恢复，可通过多因素机制来解释：（i）手术切除直接阻碍结下传导系统的主动脉瓣环钙化；（ii）室压力超负荷对间隔内传导系统的压力减轻；（iii）如本患者酒精敏感型晕厥所表现的明显自主神经失调改善，这是由于心室压力卸载影响左心室机械感受器的结果。
