1.Department of Cardiology, Central Hospital of Wuhan City, Wuhan 430014, Hubei, China; 2.Department of Cardiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430014, Hubei, China
AIM To evaluate the diagnostic value of bipolar esophageal electrocardiogram in septal dormant atrioventricular accessory pathway. METHODS Nineteen patients with septal dormant atrioventricular accessory pathway, diagnosed by electrophysiological study and radiofrequency ablation, were chosen to receive transoesophageal atrial pacing to induce the onset of paroxysmal superventricular tachycardia (PSVT). The 12 leads superficial ECG, unipolar and bipolar esophageal ECG were recorded during the whole process of transoesophageal electrophysiological study. The shape and polarity of P wave and the relationship between P wave and QRS complex were observed in each ECG. The duration and voltage of P wave were measured and the difference of the diagnosis veracity of the septal dormant atrioventricular accessory pathway was compared between the unipolar and bipolar esophageal ECG using the results obtained by the invasive electrophysiological mapping as the golden standard. RESULTS There was no polar change of P wave in unipolar esophageal ECG while the polarity of P wave could be adjusted according to the need in the bipolar ECG. Though the duration of P wave had no statistical difference between the unipolar and bipolar esophageal ECG (96±11)ms vs (99±14)ms, the voltage of P wave was statistical higher in bipolar esophageal ECG than that in unipolar esophageal ECG (0.58±0.12)mV vs (0.36±0.11)mV, P<005). With the results obtained from electrophysiological studies as the standard, the diagnostic veracity of septal dormant atrioventricular accessory pathway of unipolar and bipolar esophageal ECG were 58% and 89% respectively (P<005). CONCLUSION The bipolar esophageal ECG is more reliable than unipolar esophageal ECG in the diagnosis of septal dormant atrioventricular accessory pathway, because the former can record the P wave with higher voltage and displays the P waves more clearly.