Effects of P-wave dispersion on atrial fibrillation in patients with acute anterior wall myocardial infarction

Backround: P-wave dispersion (P dispersion), defined as the difference between the maximum and the minimum P-wave duration (P minimum), and maximum P-wave duration (P maximum) have been used to evaluate the discontinuous propagation of sinus impulse and the prolongation of atrial conduction time respectively. The aim of this study was to investigate whether early assessment of P dispersion predicts paroxysmal atrial fibrillation (AF) in patients with acute anterior wall myocardial infarction (MI). Methods: We prospectively evaluated 147 consecutive patients (45 women, 102 men; aged 55 9 years) with a first acute anterior wall MI. All patients were evaluated by echocardiography to measure the left atrial diameter and left ventricular ejection fraction (LVEF). Electrocardiography was recorded from all patients on admission and every day during hospitalization. Results: AF occurred in 25 patients. In 122 patients, AF did not occur. P maximum was found to be significantly higher in patients with AF than in patients without AF (115 +/- 17.3 ms vs 101 +/- 14.7 ms, P = 0.001). P dispersion also was significantly higher in patients with AF than in patients without AF (50 +/- 12.5 ms vs 43 +/- 10.1 ms, P = 0.01). There was no significant difference between the two groups in P minimum (64 +/- 12.5 ms vs 59 +/- 11.7 ms, P = 0.057). The echocardiographically left atrial diameters were not significantly higher in the patients with AF than those without (25 3.38 mm and 23 +/- 3.36 mm, respectively, P = 0.76). LVEF was found to be significantly different in the patients who developed AF and in those who did not (37.96 +/- 6.18% vs 47.70 +/- 6.01%, P = 0.0001). Conclusions: Although P maximum and P dispersion are significant predictive factors of AF in patients with acute anterior wall Mi in the univariate analysis, on the basis of multivariate analysis, only age and LVEF were independent predictive parameters for AF.