Revault d'Allonnes G, Pavin D, Lebreton H, Leclercq C, Gras D, Daubert C, Mabo P
Service de cardiologie A, CHRU, l'Hôtel-Dieu, Rennes.
Arch Mal Coeur Vaiss. 1997 Dec;90(12):1637-43.
Mahaim fibres are rare, right sided accessory pathways comparable with respect to certain properties (slow, decremential conduction) with "accessory atrioventricular node" located on the lateral tricuspid annulus at a distance from the Aschoff-Tawara node. Atriofascicular and atrioventricular fibres may be distinguished, both responsible for wide complex tachycardia (left bundle branch block pattern with left axis deviation). The authors report a series of 8 patients (6 women, 2 men: age: 27 +/- 11 years) without underlying cardiac disease, incapacitated by episodes of antidromic reciprocating tachycardia related to the atriofascicular fibres and justifying the indication of treatment by endocavitary ablation. In all cases, the authors tried to identify a specific potential of the Mahaim fibres on the lateral aspect of the tricuspid annulus. When the potential was recorded (7 out of the 8 cases) ablation was successful (procedure time 160 +/- 11 min; average number of applications: 9). It was not possible to identify a specific Mahaim potential in 1 case and so ablation was performed on the distal right ventricular site of insertion with no criterion of efficacy. In one woman, manipulation of the ablation catheter led to prolonged mechanical block in the Mahaim fibres, so suppressing the usual criteria of evaluation of the initial result of ablation: an early recurrence of tachycardia was observed in this case. No complications occurred during the 8 procedures. These results and those of other published cases, showed that radiofrequency ablation of Mahaim fibres is feasible with a high success rate without any immediate or long-term complications. This reliable and effective technique should form one of the therapeutic options for these invalidating junctional tachycardias.
Mahaim纤维较为罕见，是右侧的旁路，在某些特性（缓慢、递减传导）方面与位于三尖瓣环外侧、远离阿绍夫-陶拉腊结的“房室旁结”相当。可区分房束纤维和房室纤维，二者均可导致宽QRS波心动过速（呈左束支传导阻滞图形伴电轴左偏）。作者报告了一组8例患者（6例女性，2例男性；年龄：27±11岁），无基础心脏病，因与房束纤维相关的逆向折返性心动过速发作而失能，证明了心腔内消融治疗的适应证。在所有病例中，作者试图在三尖瓣环外侧识别Mahaim纤维的特定电位。当记录到该电位时（8例中的7例），消融成功（手术时间160±11分钟；平均放电次数：9次）。1例未能识别出特定的Mahaim电位，因此在右心室插入远端部位进行消融，无疗效标准。在1例女性患者中，消融导管的操作导致Mahaim纤维出现长时间的机械性阻滞，从而抑制了评估消融初始结果的常用标准：该病例中观察到心动过速早期复发。8例手术均未发生并发症。这些结果以及其他已发表病例的结果表明，Mahaim纤维的射频消融是可行的，成功率高，无任何即刻或长期并发症。这种可靠且有效的技术应成为这些导致失能的交界性心动过速的治疗选择之一。
