Atrial activation analysis by surface P wave and multipolar esophageal recording after cardioversion of persistent atrial fibrillation.
We studied atrial activation during sinus rhythm by combining 12-lead ECG and multipolar esophageal recordings in 30 patients after electrical cardioversion of persistent atrial fibrillation. The primary endpoint was to establish a correlation between atrial activation evaluated by the two methods. Total P wave duration and morphology in inferior leads identified three patterns: normal P wave, late-positive P wave, and late-negative P wave. Proximal and distal esophageal recording characterized the longitudinal direction of activation of the posterior left atrium. We distinguished three activation patterns: normal activation when the interatrial conduction time is normal and depolarizes in craniocaudal direction, delayed activation when the interatrial conduction time is prolonged and the craniocaudal activation is maintained, and finally reversed activation when the posterior left atrium depolarizes in a reversed caudocranial direction. Four patients showed a normal P wave and also had a normal esophageal activation. Twelve patients showed a prolonged P wave (associated with delayed esophageal activation in 10 patients and reversed activation in 2 patients); 14 patients had a late-negative P wave (all associated with a reversed esophageal activation). A high correlation existed between each pattern obtained by surface ECG and esophageal recording (P < 0.001) and between surface P wave duration and interatrial conduction time (R2 = 0.64, P < 0.001). Much information concerning atrial activation can be obtained by meticulous analysis of the P wave, particularly its terminal part. Multipolar esophageal recording can be used when surface ECG appears unclear.