Morphological characteristics of P waves during selective pulmonary vein pacing

OBJECTIVES We sought to assess the value of 12-lead electrocardiogram (ECG) P-wave morphology to recognize the paced pulmonary vein (PV). BACKGROUND Prediction of arrhythmogenic PVs producing ectopy or initiating atrial fibrillation (AF) using 12-lead ECG may facilitate curative ablation . METHODS In 30 patients P-wave configurations were studied during sinus rhyt hm and during pacing at six sites from the four PVs: top and bottom of each superior PV and both inferior PVS. The P-wave amplitude, duration and morp hology were assessed, and predictive accuracies were calculated for the mos t significant parameters. An algorithm predicting the paced PV was develope d and prospectively evaluated in a different population of 20 patients. RESULTS Three criteria were used to distinguish right from left PV: 1) a po sitive P-wave in lead aVL and the amplitude of P-wave in. lead 1 greater th an or equal to 50 muV indicated right PV origin (specificity 100% and 97%, respectively); 2) a notched P-wave in lead II was a predictor of left PV or igin (specificity 95%); and 3) the amplitude ratio of lead III/II and the d uration of positivity in lead V-1 were also helpful in distinguishing left versus right PV origin. In addition, superior PVs could be distinguished fr om inferior according to the amplitude in lead II (greater than or equal to 100 muV). In prospective evaluation, an algorithm based on the above four criteria identified 93% of left versus right PV and totally 79% of the spec ific PVs paced. CONCLUSIONS Pacing from the different PVs produced a P-wave with distinctiv e characteristics that could be used as criteria in an algorithm to identif y the PV of origin with an accuracy of 79%. (J Am Coll Cardiol 2001;38:1505 -10) (C) 2001 by the American College of Cardiology.