RESUMO
To evaluate how the duration of atrial fibrillation before cardioversion affects the recovery of atrial systolic function, serial transthoracic pulsed Doppler echocardiographic studies were performed within 2 hours and at 2 days, 7 days, 1 month and 2 months after chemical cardioversion to sinus rhythm. Peak A wave velocity (A), velocity time integral of A wave (A-VTI) and percent A-wave filling (A/VTI-tot) were assessed in 60 patients with lone atrial fibrillation of brief (> or = 12 to < or = 72 hours, 20 patients), moderate (> 72 hours to < or = 4 weeks, 20 patients) or prolonged (> 4 to < or = 24 weeks, 20 patients) duration. The three groups were well matched for age and left atrial size and none of the patients underwent antiarrhythmic therapy during follow-up. Atrial mechanical function is greater immediately and at 2 and 7 days after cardioversion in patients with brief atrial fibrillation, as compared moderate and prolonged atrial fibrillation (A and A/VTI-tot values: p < 0.05, p < 0.005 and p < 0.05, respectively). In addition, at 7 days after cardioversion, atrial systolic function is greater in patients with moderate atrial fibrillation as compared to prolonged atrial fibrillation (A value, p < 0.005 and A/VTI-tot value, p < 0.05). In all groups, atrial mechanical function increases over time and ultimately achieves similar levels. Full recovery of atrial mechanical function is achieved within 2 days in patients with brief atrial fibrillation, within 7 days in patients with atrial fibrillation of moderate duration and within 1 month in patients with prolonged atrial fibrillation. Recovery of the mechanical function of the left atrium is related to the duration of atrial fibrillation before cardioversion. These findings have important implications for assessing the early hemodynamic benefits of successful cardioversion.
