微 P′型房性心动过速由于 P′微小,合并A-VB 而室律不齐时易误诊为房颤或房扑。现报告1例。患者女性,71岁。心慌、气促、反复双下肢浮肿7年。临床诊断:原发性扩张型心肌病,全心扩大,心功能Ⅳ级。未用洋地黄。附图示:常规12导联心房波电压微小,易误诊为“f”波。S_5导联可见倒置的 P′波。P′-P′间距0.26s,频率230次/min,节律匀齐,P′-P′间有等电位线,符合房速。QRS 波呈 CRBBB+LAB Micro-P ’type atrial tachycardia due to P’ small, combined with A-VB and irregular room when misdiagnosed as atrial fibrillation or atrial flutter. Now report 1 case. Patient female, 71 years old. Flustered, shortness of breath, repeated lower extremity edema for 7 years. Clinical diagnosis: Primary dilated cardiomyopathy, heart full expansion, cardiac function Ⅳ level. Unused digitalis. Attached figure: conventional 12-lead atrial wave voltage is small, easily misdiagnosed as “f” wave. S_5 lead visible inverted P ’wave. P’-P ’pitch 0.26s, the frequency of 230 beats / min, uniform rhythm, P’-P’ equipotential line, in line with the room rate. QRS wave was CRBBB + LAB