P-wave dispersion: a novel predictor of paroxysmal atrial fibrillation

The prolongation of intraatrial and interatrial conduction time and the inhomogeneous propagation of sinus impulses are well known electrophysiologic characteristics in patients with paroxysmal atrial fibrillation (AF). Previous studies have demonstrated that individuals with a clinical history of paroxysmal AF show a significantly increased P-wave duration in 12-lead surface electrocardiograms (ECG) and signal-averaged ECG recordings.

The inhomogeneous and discontinuous atrial conduction in patients with paroxysmal AF has recently been studied with a new ECG index, P-wave dispersion. P-wave dispersion is defined as the difference between the longest and the shortest P-wave duration recorded from multiple different surface ECG leads. Up to now the most extensive clinical evaluation of P-wave dispersion has been performed in the assessment of the risk for AF in patients without apparent heart disease, in hypertensives, in patients with coronary artery disease and in patients undergoing coronary artery bypass surgery. P-wave dispersion has proven to be a sensitive and specific ECG predictor of AF in the various clinical settings. However, no electrophysiologic study has proven up to now the suspected relationship between the dispersion in the atrial conduction times and P-wave dispersion. The methodology used for the calculation of P-wave dispersion is not standardized and more efforts to improve the reliability and reproducibility of P-wave dispersion measurements are needed.

P-wave dispersion constitutes a recent contribution to the field of noninvasive electrocardiology and seems to be quite promising in the field of AF prediction.