Effect of reperfusion on P-wave duration and P-wave dispersion in acute myocardial infarction: Primary angioplasty versus thrombolytic therapy

Background: Atrial fibrillation (AF) is a common arrhythmia occurring in about 10-20% of patients with acute myocardial infarction (AMI). P-wave dispersion (PWd) and P-wave duration (PWD) have been used to evaluate the discontinuous propagation of sinus impulse and the prolongation of atrial conduction time, respectively. This study was conducted to compare the effects of reperfusion either by thrombolytic therapy or primary angioplasty on P-wave duration and dispersion in patients with acute anterior wall myocardial infarction. Methods: We have evaluated 72 consecutive patients retrospectively (24 women, 48 men; aged 58 +/- 12 years) experiencing acute anterior wall myocardial infarction (AMI) for the first time. Patients were grouped according to the reperfusion therapy received (primary angioplasty (PTCA) versus thrombolytic therapy). Left atrial diameter and left ventricular ejection fraction (LVEF) were determined by echocardiography in all patients. Electrocardiography was recorded from all patients on admission and every day during hospitalization. Maximum (P max) and minimum (P min) P-wave durations and P-wave dispersions were calculated before and after the treatment. Results: There were not any significant differences between the groups regarding age, gender, left ventricular ejection fraction, left atrial diameter and volume, cardiovascular risk factors, and duration from symptom onset to treatment. P-wave dispersions and P-wave durations were significantly decreased after PTCA [Mean P max was 113 +/- 111 ms before and 95 +/- 17 ms after the treatment (P = 0.007)]. Mean PWd was 46 +/- 12 ms before and 29 +/- 10 ms after the treatment (P = 0.001). Also, P max and PWd were significantly lower in PTCA group (for P max 97 +/- 22 ms vs 114 +/- 16 ms and for PWd 31 +/- 13 ms vs 55 +/- 5 ms, respectively). Conclusions: Primary angioplasty reduces the incidence of AF by decreasing P max and P-wave dispersion.