发生在窦房结内或窦房结周围组织的折返现象称为窦房结折返或窦房折返。窦房结折返的资料大都来自动物实验和人类起搏测验。在自然条件下常规心电图中窦房折返现象较为罕见,现报告一例如下。患者男性,51岁,临床诊断冠心病。附图Ⅱ导联a b为连续记录,窦性P波,P— Occurred in the sinus node or around the sinus node tissue reentry phenomenon known as sinus node reentry or sinoatrial fold back. Sinus node reentry data mostly from animal experiments and human pacing test. Under normal conditions, the return of sinoatrials in conventional ECG is relatively rare, a report is as follows. Male patient, 51 years old, clinically diagnosed with coronary heart disease. Figure II lead a b for continuous recording, sinus P wave, P-