RESUMO
BACKGROUND: Electrical cardioversion of atrial fibrillation (AF) to sinus rhythm is associated with transient left atrial dysfunction and this phenomenon may lead to thrombus formation and embolic stroke. Delay of atrial mechanical function recovery may be related to ventricular diastolic function. OBJECTIVE: This study examined the effects of left ventricular diastolic function as well as the multiple clinical factors on the recovery of atrial systolic function after cardioversion for atrial fibrillation. METHODS: A total of 44 patients (28 male, 16 female, 61+/-18 years) with chronic AF (> or =1 month) underwent electrical cardioversion. Deceleration time of early filling wave (pre-CV EDT) on transmitral inflow obtained by using Doppler echocardiography before cardioversion and serial transmitral inflow Doppler variables were recorded through a 1 week study period in all patients. Various clinical (age, gender, the duration of AF) and echocardiographic variables (pre-CV EDT, left atrial dimension, left ventricular ejection fraction) were tested for an association with peak atrial filling wave velocity (VA) on day 1, 3 and 7 after cardioversion. RESULTS: EDT measured before cardioversion had a strong linear correlation with peak VA on every echocardiographic evaluation after cardioversion (Regression coefficient (R)=0.69, P<0.001; R=0.78, P<0.001 and R=0.83, P<0.001, on day 1, day 3 and day 7, respectively). The effect of left ventricular ejection fraction on peak VA was weaker than those of EDT. The duration of AF showed an inverse association with the recovery of atrial function, but this lost on multivariate analysis. None of the other parameters significantly correlated with peak VA after cardioversion. CONCLUSION: The recovery of atrial mechanical function after cardioversion, as assessed by peak VA on transthoracic Doppler echocardiography is mainly associated with the left ventricular diastolic function as measured by EDT, whereas the left ventricular systolic function relatively a small effect on this outcome. The duration of AF does not have any association with peak VA, possibly if it is chronic.
