The effect of conversion type on P wave dispersion in patients with atrial fibrillation

Aim. The aim of this study was to investigate whether conversion type of atrial fibrillation (AF) to sinus rhythm affects the P wave dispersion (PD) in patients with AF. Methods. Based on conversion type, 95 consecutive patients with AF <3 months were divided into 3 groups: spontaneous cardioversion (SC) (N.=33, mean age: 60.6±11.6 years), pharmacologic cardioversion (PC) (N.=32, mean age: 59.2±9.6 years) and electrical cardioversion (EC) (N.= 30, mean age: 65.3±10.6 years). P wave duration (maximum and minimum) were measured in 12-lead ECG, and PD was calculated. Results. Left atrial diameter and AF duration were significantly higher in EC (43.6±4.8 mm and 794.1±815.1 h) than SC (38.5±3.9 mm and 13.8±18.3 h) and PC (40.9±4.5 mm and 65.3±148.5 h) groups (P<0.01). P maximum was much longer in EC group compared with SC and PC group (121.6±9.7, 108.4±6.4 and 115.8±8.6 ms, P=0.01, respectively). There was a significant difference in PD among SC, PC and EC groups (44.4±9.2, 49.5±8.7 and 53.5±8.8 ms; P=0.005, respectively). PD correlated with AF duration (r=0.36, P=0.03), left atrial diameter (r=0.45, P=0.002) and conversion type (r=0.29, P=0.03). However, there was no significant association between PD and conversion type in multivariate analysis. The prolonged PD resulted from AF duration (P=0.01) and the left atrial size P=0.001). Conclusion. This study suggests that conversion type ofAF to sinus rhythm has no effect on P wave duration and independent of AF duration and the left atrial diameter.