患者男性,56岁,主诉反复心悸、胸闷,深呼气时心悸消失。门诊心电图检查为短阵房性心动过速(简称房速)收入住院。体检未见明显阳性体征。心电图检查《附图A、B)分别为V_1、V_3、V_5 3个导联同步连续记录。图中所示,屏气时窦性心律60次/min左右。吸气时出现连续提前的异位P′波,形态与窦性不同,P′-R间期逐渐延长, Male patient, 56 years old, complained repeatedly palpitations, chest tightness, heart failure when deep breath disappeared. Outpatient ECG examination for atrial tachycardia (referred to as atrial tachycardia) income hospitalization. Physical examination showed no significant positive signs. ECG "Figure A, B) were V_1, V_3, V_5 3 lead synchronous continuous recording. The figure shows, breath-hold sinus rhythm 60 times / min or so. During inhalation, continuous advance ectopic P ’wave appeared, the morphology and sinus were different, P’-R interval gradually extended,