特发性左心室心动过速致心律失常基质的电解剖差异

Anatomical variability of arrhythmogenic substrate in idiopathic left ventricular tachycardia

目的 探索特发性左心室心动过速（ILVT）和房室折返性心动过速（AVRT）患者左心室传导系统和缓慢传导区电解剖变异情况.方法 选取2009年5月至2011年12月20例成功消融的ILVT患者（ILVT组）,年龄20～51（37±7）岁,男16例；26例AVRT患者（对照组）,年龄25～51（38±8）岁,男20例,窦性心律下分别建立左心室三维电解剖标测,标记左心室传导系统、缓慢传导区及其交汇区,分析变异情况.ILVT组患者依据消融关键区和拖带刺激进行消融.结果 根据浦肯野电位分布将传导系统变异分为3个亚型：两分支、三分支和扇形分布于左心室间隔,两组间各分支长度差异无统计学意义（P＞0.05）.缓慢传导区在ILVT中亦存在变异：17例位于后下间隔,1例位于下间隔近心尖处,2例于中、后间隔处.浦肯野电位和舒张期电位间存在面积约（1.5±0.4） cm2的交汇区,该处拖带和消融均取得成功.6例AVRT患者于后下间隔处记录到缓慢传导区,长度[12.0～28.7 （20.4±4.7） mm对11.8～ 20.3（16.1±3.3） mm,t=2.1,P=0.048]、面积[1.6～ 3.5（2.5±0.5） cm2对1.4～2.1 （1.8±0.3） cm2,t=3.0,P=0.006]显著小于ILVT组.结论 左心室传导系统和缓慢传导区存在多种变异,使ILVT折返机制更为复杂.

Objective The purpose was to investigate the anatomical variability of left ventricular conduction system（LVCS） and slow conduction zone （SCZ） in patients with idiopathic left ventricular tachycardia （ILVT） and atrioventricular reentrant tachycardia（AVRT）.Methods Twenty patients with ILVT and twentysix AVRT subjects were studied.Electroanatomical mapping was performed in left ventricular during sinus rhythm.The anatomic aspects of LVCS,SCZ and the junction area were investigated.Radiofrequency ablation application was delivered on the basis of junction area and entrainment.Results According to the distribution of Purkinje potential,LVCS was distinguished into 3 types：two discrete fascicles without interconnections,three separate fascicles and fanlike structure distribution over the septal surface broadly.There was no statistical differences in the length of them in two groups （P〉0.05）.In ILVT group,SCZ was located at inferoposterior septum in 17 patients,at posterior and mid-septal with 2 SCZs in 2 patients and at inferior apex in 1 patient.A crossover junction area with Purkinje potential and diastolic potential was recorded in all patients with the size of （1.5 ± 0.4） cm2.The length [12.0～28.7（20.4±4.7） mm vs 11.8～20.3（16.1±3.3）mm,t=2.1,P=0.048]and size of diastolic potential [1.6～ 3.5 （2.5±0.5） cm2 vs 1.4 ～ 2.1 （1.8±0.3） cm2,t =3.0,P =0.006] of AVRT group were significantly smaller than those of ILVT group.Concealed entertainment and/or ablation were obtained successfully in all patients at this area.Conclusion Left bundle branch and its fascicles and SCZ had much anatomical variability,which may make the electrophysiologic mechanism of ILVT complicated.