射频消融房室交界区慢、快经区域对犬和人心房颤动时心室率的影响

Control of Rapid Ventricular Response by Radiofrequency Catheter Modification of the Atrioventricular Node in Dogs and Patients with Atria) Fibrillation.

本文观察经导管射频消融房室交界区慢、快径区域对大和人心房颤动时心室率的影响.方法 杂种犬4条,体重11±1.2kg.房室结折返性心动过速患者7例,年龄29～65岁.阵发性房颤患者4例,年龄62～70岁,其中2例为短P-R间期综合征.均先采用“下位法”消融慢径区域后,若房室结有效不应期或房颤时平均R-R间期无明显变化,则加行“快径”区域消融.房颤诱发采用猝发脉冲电刺激(人)或静滴氯化乙酰胆碱后猝发脉冲电刺激(犬).结果 7例房室结折返性心动过速患者中5例经下位法射频消融阻断慢径,房室结前传有效不应期及诱发房颤时平均R-R间期明显延长(222±33ms vs 285±42ms和539±44ms vs 656±53ms P<0.01),无并发症.4条大及4例阵发性房颤患者经心内电生理检查证实均无房室结双径路表现,选择性消融“慢径区域”后,房室结有效不应期和房颤时平均R—R间期无明显变化,加行“快径区域”消融后,房室结有效不应期和房颤时平均R—R间期明显延长(犬145±16ms vs 185±22ms和305±13ms vs 403±17ms P<0.01,人220ms vs 490ms和367ms vs 690msP<0.01),1例房颤患者术后3天出现Ⅲ°AVB,2周后恢复为Ⅰ°AVB.本文还在动物实验中观察到消融快径区域时,房侧靶点(A/V>1)较室侧靶点(A/V<1)更易于造成Ⅲ°AVB.结论 选择性射频消融慢径区域对减?

Objective The aim of this study was to analyze the effect of radiofrequency catheter modification of the a-trioventricular node for control of the rapid ventricular response in dogs and patients with induced or paroxysmal a-trial fibrillation. Methods 4 dogs, weight 11±1. 2kg; 4 patients with paroxysmal atrial fibrillation and 2 with short P-R interval; 7 patients with atrioventricular nodal reentry tachycardia (AVNRT). Selective radiofrequency catheter ablation of the'slow'atrioventricular nodal pathway position was performed with a stepwise approach in dogs and patients. If the technique can not effectively control the ventricular response to atrial fibrillation, radiofrequency energy was applied near the compact atrioventricular node or His bundle (i.e. 'fast' atrioventricular nodal pathway position). Sustained atriail fibrillation was induced with burst stimulation or IV methacholine. The alrioventricular nodal refractoriness and the ventricular rate during induced atrial fibrilation was assessed at baseline and after a selective ablation of'slow'and 'fast' atrioventricular nodal pathway position. Results After a selective 'slow' atrioventricular nodal pathway position ablation, the atrioventricular nodal dual-pathway physiology of 5 among the 7 patients with documented AVNRT was abolished, the atrioventricular nodal refractoriness and R-R interval during induced atrial fibrillation were significantly prolonged in these patients, but not in 4 dogs and 4 patients with paroxysmal atrial fibrillation in whom dual atrioventricular nodal pathway physiology was not demonstrated. The atrioventricular nodal refractoriness and R-R intervai during induced atrial fibrillation of these dogs and patients were significantly prolonged after a selective 'fast' atrioventricular nodal pathway position ablation. Conclusion Selective atrioventricular nodal 'slow' pathway position ablation may be a safe and effective method for control of the rapid ventricular response to atrial fibrillation in patients with dual atroventricuiar nodal pathway. For the patients without dual atrioventricular nodal pathway the effect of this technique depend upon the refractoriness differences between the'slow'and 'fast' atrioventricular nodal pathway positions.