Ometto R, Thiene G, Corrado D, Vincenzi M, Rossi L
Department of Cardiology, City Hospital, Vicenza, Italy.
Eur Heart J. 1992 Nov;13(11):1579-84. doi: 10.1093/oxfordjournals.eurheartj.a060104.
The basic anatomical substrate of enhanced A-V nodal conduction, manifesting or not as Lown-Ganong-Levine syndrome, is still a controversial issue. We describe the case of a 34-year-old man who presented episodes of ventricular fibrillation. Electrophysiological studies showed that the AH interval was 55 ms, and increased by only 20 ms at paced cycle lengths of 300 ms; atrial pacing induced atrial fibrillation, with a shortest RR interval of 240 ms. Despite verapamil therapy, this patient died suddenly at home. Histological study disclosed a severe A-V node hypoplasia that was evidently congenital in nature; the rest of the conduction system was normal, and no accessory A-V pathways were present. We suggest that enhanced A-V nodal conduction in this patient was due to the developmental defect in the A-V node; this abnormality caused a loss of specific impulse-delaying function, and thus allowed rapid, unfiltered atrial impulses to reach the lower A-V junction and ventricles.
房室结传导增强的基本解剖学基础，无论是否表现为洛恩-加农-莱文综合征，仍然是一个有争议的问题。我们描述了一名34岁男性出现室颤发作的病例。电生理研究显示AH间期为55毫秒，在300毫秒的起搏周期长度时仅增加20毫秒；心房起搏诱发心房颤动，最短RR间期为240毫秒。尽管接受了维拉帕米治疗，该患者仍在家中突然死亡。组织学研究显示严重的房室结发育不全，显然是先天性的；传导系统的其余部分正常，且不存在附加房室通路。我们认为该患者的房室结传导增强是由于房室结的发育缺陷；这种异常导致特定冲动延迟功能丧失，从而使快速、未经滤过的心房冲动到达低位房室交界区和心室。
