Hluchy J, Schickel S, Schlegelmilch P, Jörger U, Brägelmann F, Sabin G V
Department of Cardiology and Angiology, Elisabeth Hospital, Essen, Germany.
Europace. 2000 Jan;2(1):42-53. doi: 10.1053/eupc.1999.0069.
Most atrioventricular accessory pathways (AV-APs) exhibit Kent bundle physiology characterized by fast and non-decremental conduction properties. In contrast, atriofascicular APs, which are only capable of reaching slow levels of long antegrade decremental conduction, are uncommon. The aim of this study was to describe antegrade and/or retrograde AV-APs with unusual decremental properties.
Five patients with unusual decremental AV-APs underwent electrophysiological evaluation and radiofrequency catheter ablation for symptomatic tachycardias. Three were found to have structural heart disease, and three latent decremental AV-APs in the anterograde and/or retrograde direction that could not be demonstrated by routine electrophysiological testing. In Case 1, a right posteroseptal AV-AP with bidirectionally latent decremental conduction was associated with clinical antidromic circus movement tachycardia (CMT) mimicking ventricular tachycardia and orthodromic CMT, the latter inducible only with isoprenaline. In Case 2, incessant orthodromic CMT was due to a latent retrograde left posterolateral AV-AP. In both cases, double atrial responses to a single paced ventricular beat, initiating orthodromic CMT, were observed. In Case 3 with latent preexcitation unmasked by adenosine and atrial pacing, retrograde latent decremental conduction over a right posteroseptal AV-AP could be shown only with isoprenaline. This patient and the remaining two with overt preexcitation demonstrated anterograde decremental AP conduction that was discontinuous over a right posteroseptal AV-AP in Cases 3 and 4 and was continuous over a midseptal AV-AP in Case 5. In the latter case, the site of decremental conduction could be localized at the proximal AP origin. All five AV-APs were successfully ablated at the annulus level.
AV-APs with unusual decremental properties that are either latent, demonstrable only during CMT or overt, exhibiting functional longitudinal dissociation are described. These APs could be identified and successfully ablated after detailed electrophysiological analysis.
大多数房室旁道（AV-APs）表现出Kent束生理特性，其特征为快速且非递减性传导特性。相比之下，仅能达到缓慢程度的长程前向递减性传导的房室束旁道则较为罕见。本研究的目的是描述具有不寻常递减特性的前向和/或逆向AV-APs。
5例具有不寻常递减性AV-APs的患者因有症状性心动过速接受了电生理评估和射频导管消融治疗。其中3例存在结构性心脏病，3例在前向和/或逆向方向存在隐匿性递减性AV-APs，常规电生理检查无法证实。病例1中，一条具有双向隐匿性递减传导的右后间隔AV-AP与临床逆向折返性心动过速（CMT）酷似室性心动过速以及正向CMT相关，后者仅在使用异丙肾上腺素时可诱发。病例2中，持续性正向CMT是由一条隐匿性逆向左后外侧AV-AP所致。在这两个病例中，均观察到对单个心室起搏刺激的双房反应，引发了正向CMT。病例3中，腺苷和心房起搏未掩盖隐匿性预激，仅在使用异丙肾上腺素时可显示右后间隔AV-AP上的逆向隐匿性递减传导。该患者以及其余2例有显性预激的患者在病例3和4中显示右后间隔AV-AP上的前向递减性AP传导不连续，在病例5中显示中间隔AV-AP上的前向递减性AP传导连续。在后者病例中，递减传导部位可定位于AP近端起源处。所有5条AV-APs均在瓣环水平成功消融。
描述了具有不寻常递减特性的AV-APs，这些特性要么是隐匿性的，仅在CMT期间可显示，要么是显性的，表现为功能性纵向分离。经过详细的电生理分析，这些旁道可以被识别并成功消融。
