P Wave Separation after Atrial Compartment Operation for Atrial Fibrillation

Abstract

LO, H-M., ET AL.: P Wave Separation After Atrial Compartment Operation for Atrial Fibrillation. Surgically induced abnormalities in atrial conduction could result in unusual P wove changes. A 31-year-old woman underwent concomitant mitral valve surgery and atrial compartment operation for mitral stenosis and atrial fibrillation (AF). After operation, the AF was successfully converted to sinus rhythm , whereas an unusual electrocardiogram (ECG,) with a discrete negative deflection before the T wove in V-1 was noted. Electrophysiological study showed a marked conduction delay from the high right atrium (HRA) to the right atrial appendage (RAA) compartment, which resulted in a separation of P waves. The P wove preceding the QRS complex represented the activation of sinus node and the left atrial compartments, and the P at the vicinity of T wave represented the activation of RAA compartment. The conduction from HRA to RAA was worsened on HRA pacing at a faster rate, and improved after isoproterenol infusion. This report demonstrated that conduction across a surgically created isthmus in the atrium could be severely impaired and result in unusual P wave separation.