Echocardiographic factors predictive of restoration and maintenance of sinus rhythm after reduction of atrial fibrillation

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia. While the arrhythmia was initially thought to be little more than a nuisance, it is now clear that AF has a significant negative impact on quality of life and a corresponding increase in both morbidity and mortality. OBJECTIVE: The aim of this study was to identify Doppler echographic patterns that allow prediction of atrial fibrillation reduction and maintenance of sinus rhythm within 12 months. PATIENTS AND METHODS: One hundred and thirty patients having permanent atrial fibrillation, recent (51) or chronic (79) are included in the study, excepting those with valvular heart disease or thyroid dysfunction. The mean age was 63.5 +/- 11.3 years. Both transthoracic and transoesophageal echocardiography was performed using a Philips SONOS 5500 Echograph, before cardioversion. Were studied: end diastolic and systolic left ventricular diameters, left ventricular ejectionnal fraction, left atrial area (LAA), left atrial diameter, left atrial appendage area and peak emptying velocities of the left atrial appendage (PeV). Sinus rhythm was re-established in 102 patients (44 having recent and 58 chronic atrial fibrillation). Sinus rhythm was maintained for 12 months in 79 patients. RESULTS: Within the echographic parameters studied, the left atrial area (LAA) and peak emptying velocities of left atrial appendage (PeV) before cardioversion were the best predictors of restoration of sinus rhythm. On monovariate analysis, SOG is significantly lower and PicV is significantly higher in patients whose sinus rhythm had been restored in comparison with those with permanent atrial fibrillation. (Mean SOG: 27.7 +/- 7.62 vs. 34 +/- 7,6 cm2, p<0.0001; Mean PicV: 44 +/- 15.8 vs. 31.4 +/- 13,7 cm/s, p<0.0001). This difference was maintained on multivariate analysis (p=0.002 for SOG and p=0.005 for PicV). In patients with recent atrial fibrillation, only left atrial area can predict on mono and multivariate analysis (p=0.05, OR=0.5, IC=0.36 à 3.56), re-establishing of sinus rhythm whereas in patients with chronic atrial fibrillation, peak emptying velocity of left atrial appendage predict better re-establishing of sinus rhythm (p=0.04, OR=1.29, IC=0.12 à 4.23). The threshold values of LAA and PeV for conversion of atrial fibrillation into sinus rhythm are respectively 25 cm2 and 20 cm/sec. In patients who converted into sinus rhythm; LAA predict maintenance of sinus rhythm at the end of 12 months of survey (p=0.04) with a threshold value of 25 cm2. In the subgroup of patients admitted with chronic atrial fibrillation, PeV predicts better the maintenance of sinus rhythm (p=0.05) with a threshold value of 60 cm/sec, p=0.06; whereas LAA remains better in patients with a recent atrial fibrillation. (p=0.02). CONCLUSION: In addition to the anatomic study of cardiac structure and the search of intracavitary thromboses before reduction of atrial fibrillation, echocardiography allows prediction of cardioversion success (LAA and PeV) and maintenance of sinus rhythm within 12 months.