患者女,26岁,妊娠7个月。因持续性心悸,胸闷3天来院。体检:轻度气促,心率200次/分,律齐,无明显杂音闻及,两肺听诊正常,BP14/1kPa。ECG示:1.阵发性室上速;2.心肌缺血。血钾4.9mmol/L,血钠135mmol/L,血氯108mmol/L。乃拟作食道心房调搏以复律。取平卧位经鼻孔进入4极导管一根。找到双向P′波明显处。以FD-2型程控心房调搏仪(浙江电子仪器厂产)进行调搏。电压15V。以亚速刺激法不能终止心动过速。改用分级递增心房起搏法,先后以210次/分频率的电脉冲10秒,220次/分,10秒、20秒;230次/分,10秒刺激均无效后,至用230次/分的频率刺激20秒钟,出现房颤合并室速。心电图上P′波消失,代之以f波、QRS波(第1-4及6-9个),与 Female patient, 26 years old, 7 months of pregnancy. Because of persistent heart palpitations, chest tightness 3 days to hospital. Physical examination: mild shortness of breath, heart rate 200 beats / min, law Qi, no obvious noise smell, both lung auscultation normal, BP14 / 1kPa. ECG showed: 1. Paroxysmal supraventricular tachycardia; 2. Myocardial ischemia. Serum potassium 4.9mmol / L, serum sodium 135mmol / L, blood chlorine 108mmol / L. Is intended for esophageal atrial pacing to cardioversion. Take the supine into the 4-pole catheter through the nose. Find two-way P ’wave clearly at. To FD-2 type atrial pacemaker (Zhejiang Electronic Instrument Factory) pacing. Voltage 15V. Stimulation with sub-speed can not terminate tachycardia. The use of graded ascending atrial pacing method, successively to 210 times / min frequency of the electrical pulse 10 seconds, 220 times / min, 10 seconds, 20 seconds; 230 times / min, 10 seconds stimulation are invalid, Sub-frequency stimulation for 20 seconds, atrial fibrillation occurs with VT. ECG P ’wave disappears, replaced by f wave, QRS wave (1-4 and 6-9), and