腺苷对房室结双径路传导现象的诊断价值

目的 探讨腺苷对房室结折返性心动过速患者（AVNRT）房室结双径路传导现象（DAVNP）的诊断价值。方法 对53例阵发性室上性心动过速（PSVT）患者在窦性心律下经外周静脉推注递增剂量的腺苷后观察体表心电图上房室传导时间的变化。其中18例AVNRT患者在慢径消融术后行再次腺苷检查。结果 有31例慢快径咱折返性心动过速患者中有26例出现PR间期突然跳跃达60ms以上，20例房到折返性心动过速（AVRT）及2例房性心动过速（AT）中仅2例出现此现象（P＜0.01），18例AVNRT患者在慢径消融成功后电生理检查示8例慢径消失，6例存在DAVNP，但在静推腺苷时沿慢径下传的激动显著减少（P＜0.01）。结论 房室结双径路前传时快径路对腺苷的敏感性要高于慢径路，窦性心律下静脉推注腺苷是床边诊断房室结折返性心动过速患者双径路传导现象的有效方法，对心房程序扫描刺激未能发现房室传导时间跳跃时腺苷推注有助于房室结双径路的诊断。     

Value of the adenosine test for diagnosis of dual AV nodal physiology in patients with AV nodal reentrant tachycardia

Objectives: This study was aimed at assessing the value of the adenosine test for noninvasive diagnosis of dual AV nodal physiology (DAVNP) in patients with AV nodal reentrant tachycardia (AVNRT). Methods: 53 patients with paroxysmal supraventricular tachycardia (PSVT) were given incremental doses of adenosine intravenously during sinus rhythm before electrophysiological study. The adenosine test was repeated on a subset of 18 patients with AVNRT after radiofrequency catheter ablation. Results: Sudden increments of PR interval of more than 60 msec between two consecutive beats were observed in 26 (83.9%) of 31 patients with typical AVNRT and 2 (9.1%) of 22 patients with AVRT and AT (P<0.01). The maximal PR increment between 2 consecutive beats in the AVNRT group (105±45ms) was significantly greater than that in the AVRT and AT group (20±13ms) (P<0.01). In postablation adenosine test, DAVNP was eliminated in all 8 patients who underwent slow pathway abolition that EPS showed the slow pathway disappeared and 4 of 10 patients who underwent slow pathway modification that EPS showed the slow pathway persisted. Six of 10 patients who exhibited persistent duality showed a marked reduction in the number of beats conducted in the slow pathway after adenosine injection (P<0.01). Conclusions: Administration of adenosine during sinus rhythm may be a useful bedside test for diagnosis of DAVNP in high percentage of patients with typical AVNRT and additionally for evaluating the effects of radiofrequency ablation.