从射频消融探讨房室结双径路的本质和房室结改良的机制

采用两种方法对142例房室结折返性心动过速(AVNRT)患者进行房室结改良。128例慢—快型AVNRT中,83例单纯慢径改良,33例慢径前传和快径逆传同时改良,3例单纯快径逆传改良,7例快径前传和慢径或快径逆传同时改良,2例失败。1例发生永久性Ⅲ度房室传导阻滞;10例快—慢型和4例慢—慢型AVNRT患者均慢径改良成功。总成功率98.6％。平均随访6±4月,4例(2.8％)复发,均再次消融成功。慢径改良后,快径前传有效不应期、维持1:1快径前传最短的心房刺激周期明显缩短(P<0.05),而逆向快径有效不应期、维持1:1快径逆传最短的心室刺激周期无明显变化(P>O.05)。本研究提示:快径和慢径可能是解剖上不同的纤维。慢径前传和逆传可以是同一条纤维,也可以是不同的纤维;快径亦然。

Study on Nature of Dual Atrioventricular Node Pathways and Possible Mechanisms of Atrioventricular Nodal Modification From the Practice of Radiofrequency Ablation

Atrioventricular nodal modifications were performed in 142 patients with atrioventricular nodal reentrant tachycardia (AVNRT). In 128 patients with slow-fast AVNRT,slow pathways (SP) alone were modified in 83 cases. Both antegrade Sp and retrograde fast pathways(FP) were ablated in 33 eases ,retrograde FP alone were ablated in 3 eases;antegrade FP were ablated accompanying SP or retrograde FP modification in 7 cases. SP were eliminated in all 10 fastslow and 4 slow-slow AVNRT cases. Three degree AVB happened in one ease. The successful rate was 98.6％. Over a follow-up period of 6±4 months,AVNRT recurred in 4 cases (2.8％) and they were ablated suecessfully again. Antegrade FP effective refractory period (ERP) and mininal atrial pacing cycle length that maintain AV nodal 1:1 conduction were improved (P<0.05),but retrograde FP ERP and mininal ventrieular pacing cycle length that maintain AV nodal 1:1 retrograde conduction didn't change after SP ablation (P>0.05). we conclude that (1) SP may be anatomically different from FP; (2) antegrade and retrograde SP may be anatomically the same fibers or different fibers ,so as FP.