Effect of Valsalva maneuver on surface electrocardiographic P-wave dispersion in paroxysmal atrial fibrillation

The purpose of this study was to investigate the effect of the Valsalva man euver on P-wave durations and dispersion. After the Valsalva maneuver, we f ound that maximum P-wave duration increased, minimum P-wave duration decrea sed, and P-wave dispersion increased in controls, whereas the opposite was true for unselected patients with paroxysmal AF. It was concluded that pati ents with paroxysmal AF performing the Valsalva maneuver normalized their P -wave dispersion, thereby correcting the inhomogeneous intra-atrial conduct ion.