Influence of cardiac resynchronization therapy on P wave dispersion and atrial high-rate episodes

AIM To observe the impact of cardiac resynchronization therapy (CRT) on P wave dispersion (Pd) and atrial high-rate episodes (AHRE) in patients with chronic heart failure. METHODSForty-nine patients with chronic heart failure in our department from January 2009 to May 2014 were included in this study. Patients underwent CRT, 12-lead resting ECGs, 24-h Holter and echocardiograms before CRT, and 6 and 12 months after CRT. Follow-up clinic visits were required. Based on NYHA grade and echocardiograms 6 months after CRT, patients were divided into response group and non-response group. RESULTSThirty-three patients were assigned to response group and 16 to non-response group. Six months after CRT, LVEDD and ventricular premature beats (VPB) decreased and LVEF increased significantly in response group, whereas no significant differences were found in LAD, Pd, atrial premature beats (APB) and AHRE, compared with the baseline. Twelve months after CRT, LAD, Pd, APB and AHRE in response group also demonstrated significant improvement in addition to LVEDD, VPB and LVEF. However, no significant differences in non-response group were found in the above indexes 6 and 12 months after CRT. AHRE within 12 months after CRT in response group correlated positively with Pd (r=0.651, P=0.000) and no significant correlation was found with LAD (r=0.169, P=0.060). CONCLUSIONCRT can restrain the remodeling of atrium and decrease P wave dispersion and AHRE. P wave dispersion may be a strong predicting factor for AHRE after CRT.