一位77岁老年男性患者来到急诊科诉胸痛和心悸。患者既往有过两次冠脉搭桥的手术病史。12导联心电图显示单行性持续性室速在终止前演变为双向室速。室速周长为440 ms,V1导联呈右束支阻滞图形,QRS波宽140 ms(图1),心前区导联与房室分离呈正一致性。可能的起源部位是左室后下基底部(下 A 77-year-old male patient came to the emergency department to complain of chest pain and heart palpitations. The patient had previous history of surgery for coronary artery bypass surgery. 12-lead electrocardiogram showed a one-liner sustained ventricular rate evolved to bi-directional VT before termination. The VT velocity was 440 ms, the V1 lead showed a pattern of right bundle branch block, and the QRS wave width was 140 ms (Fig. 1). The precordial leads showed a positive correlation with ventricular separation. Probable sites of origin are the posterior basal base of the left ventricle (lower