[Abnormalities of electrocardiographic P wave morphology and the relationship to electrophysiological parameters of the atrium in patients with idiopathic paroxysmal atrial fibrillation].

In 39 patients with idiopathic paroxysmal atrial fibrillation (PAF group), the incidence of the abnormal P wave morphology (prolonged P wave and mitral P in lead II and increased P terminal force in lead V1: PTF V1) was examined, and the relationships to the electrophysiologic findings of the atrial muscle were investigated. The control group consisted of 42 patients with various cardiac arrhythmias other than sick sinus syndrome. P wave duration was significantly longer in the PAF group than in the control group (112 +/- 12 vs 98 +/- 10 msec, p < 0.0001). PTF V1 was greater in the PAF group than in the control group (0.051 +/- 0.018 vs 0.028 +/- 0.010 msec, p < 0.0001). P mitrale occurred in only 5 patients (12%) in the control group as compared to 25 patients in the PAF group (64%, p < 0.0001). The longest duration of the right atrial electrograms was longer in the PAF group than in the control group (101 +/- 17 vs 85 +/- 10 msec, p < 0.0001), as was the maximal number of the fragmented deflections (8.0 +/- 2.5 vs 5.8 +/- 1.4, p < 0.0001). Repetitive atrial firing zone and also fragmented atrial activity zone were longer in the PAF group than in the control group (34 +/- 24 vs 12 +/- 19 msec, p < 0.02 and 47 +/- 27 vs 24 +/- 19 msec, p < 0.001, respectively). Interatrial conduction delay zone was longer in the PAF group than in the control group (55 +/- 25 vs 38 +/- 18 msec, p < 0.001). P wave duration and PTF V1 had significant and/or borderline correlations with the longest duration of the right atrial electrocardiograms (r = 0.75, p < 0.0001 and r = 0.68, p < 0.0001, respectively), and the maximal number of its fragmented defections (r = 0.50, p < 0.002 and r = 0.40, p < 0.05, respectively). Furthermore, P wave duration had a correlation with the repetitive atrial firing zone (r = 0.55, p < 0.01). Prolonged P wave duration and increased PTF V1 are electrocardiographic indicators for the coexistence of electrophysiologic abnormalities in patients with idiopathic paroxysmal atrial fibrillation.