室上性心动过速中旁道折返的少见现象

Some rare electrophysiological phenomena in patients with paroxysmal supraventricular tachycardia

报告阵发性室上性心动过速 (PSVT)电生理检查中发现的几种少见的旁道电生理特性。例1为一左侧隐匿性房室旁道参与的房室折返性心动过速 ,其心室扫描示旁道逆向有效不应期260ms,但520～390ms时无逆向传导功能。例2为一慢_慢型房室交接区折返性心动过速 ,同时存在一条右侧隐匿性房室旁道作为旁观者。例3为一宽QRS波群心动过速 ,其体表心电图呈典型马海姆纤维型预激综合征 ,电生理揭示存在左侧房室隐匿性旁道和束室旁道两条附加旁道 ,前者为心动过速的逆传支 ,后者与房室结_希室束同为顺传支。

We report some rare electrophysiological phenomena in three patients with paroxysmal supraventricular tachycardia.In first patient,who had a left concealed atrioventricular accessory pathway and atrioventricular reentrant tachycardia,programmed ventricular extrastimulus testing revealed pathway′s retrograde block at coupling interval of 520ms,but reappearance of couduction at coupling interal of 390～270ms.In second patient,right concealed atrioventricular accessory pathway played a bystander role in its atrioventricular junctional reentrant tachycardia(slow _ slow type).Third patient′s ECG showed preexcitation of Mahaim type and he had a history of tachycardia with wide QRS,and EPS exhibited that there were a left concealed atrioventricular accessory pathway and a bundle _ ventricular pathway in heart of this patient,former being a retrograde route of tachycardia,latter as well as AVN _ His being an antergrade route,and bundle _ ventricular pathway playing a bystander role.