Value Of Transesophageal Atrial Pacing In The Localization Of Accessory Pathway During Orthodromic Atrioventricular Reentrant Tachycardia

Objective: To evalue such index as retrograde P wave(P') morphology in limb lead and lead V, and RPE interval, Pvi-PE intervalin esophagus lead during orthodromic atrioventricular reentrant tachycardia(O-AVRT) for the differential diagnosis between 0-AVRTand ;slow-fast atrioventricular nodal reentrant tachycardia (S-FAVNRT), and the localization of accessory pathway (AP). METHOD: 238 patients with successful radiofrequency catheter ablation(RFCA)were diagnosed by intracardial electrophysiology asO桝VRT mediated by single AP and S 桭 AVNRT by one mechanism. Different localization was characterized by "the Guideline for RFCA of Arrhythmias91996)" as left anterior lateral AP (LAD, left posteroseptal AP (IPS), left lateral AP (LL), right lateralAP (RL), right anteroseptal AP (RAS), right midseptal AP (RMS), right posteroseptal AP (RPS)0 The index to investingate was as follow: P' wave morphology in limb lead and lead V, , RPE interval, PVI-PE interval in esophagus lead during 0-AVRT . Results: (1) Statistically significant differentce of RPE interval was observed between 0-AVRT group and S-F AVNRT group(P<0. 01), but the number of patients in each group whose RPE interval was between 70ms and 90ms had no differentce. (2) Pvi-PE interval during 0桝VRT mediated by free wall AP had significant differentce from that during S 桭 AVNRT ( ?54. 1+12.3 ms left, 67. 3 + 14. 6ms right, vs 10.0+8.0ms P<0.01). (3) Statistically significant differentce of RPE interval was found bythe comparison between LAL , LL and IPS, but the differentce as well as that of PyrPr. interval was not observed by the comparison between RAS, RMS, RPS, between LAS, LLandLPS, respectively. (4) In left side AP, the number of P' vi positive amounts to 94.6% and that of P' i negative amounts to 76. 1%. In right side AP, the number of P' Vl negative and biphasic amounts to 90.8% totally0 Only 3 cases of right side AP had a negative P' wave in lead I, 93.0% of cases having RAS AP had positive P' wave in at least two of the three inferior leads and 86. 0% of RMS AP had negative P' wave, 92. 7% of RPS AP had a deep retrograde P' wave. Conclusion: (1) RPE interval between 70ms and 90ms had -'littlee value for the differential diagnosis between AVRT and S 桭 AVNRTo (2) The absolute value (25ms) of Pv,-PE interval can be a quantitative index to differ 0桝VRT mediated by free wall AP from S-F AVNRTo (3) Combining RP E interval and PV1-PE interval only local the AP roughly o (4) P' v, wave polarity using to distinguish leftside AP from right side AP has a higher sensitiveity, and P' i wave polarity has a higher specificity. The P' wave polarity in inferior leads favor the diagnosis of the localization of AP- anterior or posterior, especially for right septal AP. ( 5 ) In clinical cases , the characteristics of P' wave polarity in lead V1, I, AVL and RPE interval, PVI~PEinterval in esophagus lead can local AP first and roughly-left side AP, right side AP or septal AP, and then P' wave morphology can do specificly...