流出道室性心律失常：一类肌袖性心律失常

流出道（ventricular outflow tract,VOT）起源的室性心律失常（ventricular arrhythmia,VA）是最常见的临床心律失常.导管消融是最有效的治疗方法.这些部位的流出道VA共同靶点特征：靶点窦律下可记录到V波后高频低振幅电位（P2）,室早或室速时P2成分电位翻转,明显提前体表QRS-30ms以上（Pl）,90％以上流出道VA可记录到此类特殊电位,预示消融成功;而非靶点部位无此特殊电位.解剖研究提示,心室流出道存在肌袖性优势传导束,部分向肺动脉/主动脉瓣上延伸,这种特殊性靶点电位被认为与流出道肌袖传导有关.临床标测流出道VA靶点结构包括心律失常起源起源点-肌袖性传导通路-心室突破口,肌袖传导长短不等,最长达3 cm.但是令人疑惑的是,尽管消融成功,42％消融后肌袖电位仍然存在.流出道VA与肌袖性传导密切相关,但其确切机制仍需深入研究.

Outflow Tract Ventricular Arrhythmia-A Class of Muscular Sleeve Arrhythmia

Outflow tract ventricular arrhythmia is the most common clinical arrhythmia. Catheter ablation is the most effective method of treatment, the common target characteristics of VA at these parts of the outflow tract are as follows： the V wave high frequency and low amplitude potentials can be recorded at the target of sinus rhythm（P2）, when ventricular tachycardia or ventricular premature potentials P2 component turnover, which obviously advance surface above QRS-30ms（P1）. More than 90% of the outflow tract VA could record such special potentials; non-target site is no such special potential. Anatomical studies suggest thai ventricular outflow tract exists muscular sleeve conduction bundle, portion extends to the pulmonary / aortic valve. This special target potential is known to be associated with the outflow cuff conduction. Through clinical mapping, VA target structure of outflow tract includes arrhythmia origin pointmuscular sleeve pathwayventrieular breakthrough. Muscular sleeve conduction is of unequal length, up to 3 cm. The puzzle is that despite the successful ablation after ablation 42% of muscle sleeve potential still exists. Outflow tract VA is closely related to muscular sleeves conduction, but its exact mechanism still needs further study.