Mbarek Dorra, Naccache Soufia, Abdallah Meya, Tlili Rami, Ben Ameur Youssef, Boujnah Mohamed Rachid
Tunis Med. 2017 Feb;95(2):145-148.
Hisian extrasystoles originate from the His bundle. They are rare and usually misdiagnosed. In fact, they manifest on the EKG, with a p' wave located before, in or after the QRS complex. More rarely, the extrasystole blocks the propagation of the influx to the ventricles simulating a Mobitz II atrioventricular (AV) block. We report the case of a 36-Year-old woman with no medical History, suffering from presyncope and palpitations at rest. Her physical examination and EKG were normal. The 24-hour Holter monitoring showed some long periods with unexpected blocked p waves but with no significant pause. Considering her young age and the absence of causes of AV block, we performed an intracardiac electrophysiological study which showed hisian extrasystoles with normal conduction tissue properties at baseline and under flecainide. The diagnosis of hisian extrasystoles simulating Mobitz II AV block was made. A simple monitoring with beta-blockers therapy was recommended. Hisian extrasystoles may simulate first or second degree AV block with different therapeutic and prognostic implications. Nevertheless, these hisian extrasystoles may be the marker of a vulnerable AV conduction, long-term follow up should be considered.
希氏束期前收缩起源于希氏束。它们很罕见，通常会被误诊。事实上，它们在心电图上有表现，P'波位于QRS波群之前、之中或之后。更罕见的是，期前收缩会阻断激动向心室的传导，模拟莫氏Ⅱ型房室传导阻滞。我们报告一例36岁无病史女性，静息时出现先兆晕厥和心悸。她的体格检查和心电图均正常。24小时动态心电图监测显示有一些长时间意外的P波受阻，但无明显长间歇。鉴于她年轻且无房室传导阻滞的病因，我们进行了心内电生理研究，结果显示在基线状态及服用氟卡尼时希氏束期前收缩伴有正常的传导组织特性。诊断为希氏束期前收缩模拟莫氏Ⅱ型房室传导阻滞。建议采用β受体阻滞剂进行简单监测。希氏束期前收缩可能模拟一度或二度房室传导阻滞，具有不同的治疗和预后意义。然而，这些希氏束期前收缩可能是房室传导易损性的标志，应考虑进行长期随访。
