中文摘要：

目的研究碘化N-正丁基氟哌啶醇（F2）对离体大鼠心脏传导系统的作用。方法Langendorff灌流离体大鼠心脏，记录希氏束电图和心外膜心电图，并采用外刺激技术观察F2对大鼠心脏传导系统各间期及不应期的影响。结果F2主要作用于A-H间期，延长房室传导时间，延长房室结有效不应期，并呈量效关系；而对S-A间期和H-V间期影响相对较小。但在较大剂量时也可延长S-A间期和H-V间期，使心房有效不应期和心室有效不应期延长。结论F2主要作用于房室结，减慢房室结传导，延长房室结有效不应期，这可能是F2通过终止房室结折返而发挥抗心律失常作用的主要机制。

英文摘要：

Aim To study the effects of N-n-butyl haloperidol iodide （ F2 ） on the conduction system of rat isolated hearts. Methods The Langendorff-perfused rat hearts were used in this study and the His bundle electrogram （HBE） and the electrocardiogram （ECG） were continuously recorded during constant pressure perfusion. The effects of F2 on the conduction system intervals and the refractory periods were observed under the external stimuli. Results F2 prolonged principally the atrioventricular nodal conduction time （A-H interval） and the atrioventricular node effective refractory period （AVNERP） in a concentration-dependent manner. But F2 only prolonged the intra-atrial conduction time （S-A interval）, His-Purkinje conduction time （H-V interval）, atrial effective refractory period and ventricular effective refractory period in high concentration. Conclusion F2 principally slowed the atrioventricular nodal conduction and prolonged AVNERP, which is maybe the antiarrhythmic mechanism of F2 by interrupting the atrioventricular nodal reentry.