Association of P wave duration and dispersion with the risk for atrial fibrillation: practical considerations in the setting of coronary artery disease.

P wave dispersion (PWD) is defined as the difference between maximum P wave duration (Pmax) and minimum P wave duration recorded from multiple surface electrocardiogram (ECG) leads. An increase in PWD indicates heterogeneous intraatrial and interatrial conduction and discontinuous anisotropic propagation of sinus impulses, providing a substrate that favors reentry mechanisms. Prolonged Pmax and increased PWD have been suggested to represent independent predictors for atrial fibrillation (AF). The distinctive atrial electrophysiological peculiarity featured by slow interrupted propagation of atrial impulses could be reflected by an increase in PWD predisposing to AF. Coronary artery disease (CAD) is also a well-known risk factor for AF. There are some potential mediators between CAD and AF. The noninvasive nature of P wave duration and PWD with their comparative simplicity makes these parameters attractive options; however, standards involving precise assessment are still lacking. Further exploration of the exact determinants for P wave duration and PWD would help establish the practical usefulness of these surface ECG markers in estimating the risk for AF occurrence and recurrence.