Stunning of the left atrium after conversion of atrial fibrillation: predictor for maintenance of sinus rhythm?

Recurrence of atrial fibrillation (AF) after cardioversion (CV) to sinus rhythm (SR) is determined by various clinical and echocardiographic parameters. The aim of this study was to determine the value of mitral inflow A-wave velocity, performed at 24 hours after CV in estimation of AF recurrence. The study group consisted of 187 consecutive patients with nonvalvular atrial fibrillation, who had been cardioverted to SR from 1998 to 2000. Transthoracic echocardiography was performed in all cases recruited for the study 24 hours after CV. Left atrial (LA) diameter, left ventricular ejection fraction, and mitral inflow A-wave velocity were measured. The patients were evaluated in five groups according to their recurrence time (<30 days, 31-90 days, 91-180 days, 181-365 days, and >365 days). Maintenance of SR was determined to have a negative linear correlation with age (r =-0.97, P = 0.006), LA diameter (r =-0.93, P = 0.02), and AF duration (r =-0.93, P = 0.02), while having a positive linear correlation with mitral inflow A-wave velocity (r = 0.96, P = 0.008). In the maintenance of sinus rhythm, age, LA diameter, and AF duration were not affected from the method of CV, while mitral inflow A-wave velocity was found to be affected with the method of CV. No relationship was determined between mitral inflow A-wave velocity and the maintenance of sinus rhythm in those performed electrical cardioversion, while frequency of recurrence was found to be higher in those with slow mitral inflow A-wave velocity who were performed pharmacological cardioversion (r = 0.89, P = 0.004). In conclusion, age, duration of AF, LA diameter, and the mitral inflow A-wave velocity can be used to predict the maintenance of SR after CV.