Early Restoration of Atrial Contractility After New-Onset Atrial Fibrillation in Off-Pump Coronary Revascularization
BACKGROUND: Duration of anticoagulation therapy is one of the major concerns about management of new-onset atrial fibrillation (AF) after myocardial revascularization. We evaluated whether right and left atrial contractility was restored early after electrical sinus conversion in patients who experienced new-onset AF after off-pump coronary artery bypass grafting.
METHODS: From January 2009 to December 2010, 62 patients who underwent off-pump coronary artery bypass grafting and experienced new-onset AF were prospectively enrolled. Right and left atrial contractility was evaluated with transthoracic echocardiography performed 23 ± 10 hours after restoration of sinus rhythm. Anticoagulation was initiated when the AF continued for more than 24 hours.
RESULTS: New-onset AF occurred at 2.3 ± 1.2 postoperative days, and continued or recurred for 26 ± 31 hours (>24 hours in 22 patients). Right and left atrial contractility was demonstrable after sinus conversion in all patients. Mitral inflow E and A wave velocities and the E/A ratio were 0.71 ± 0.21 m/s, 0.68 ± 0.19 m/s, and 1.15 ± 0.57, respectively. Mitral valve A’ velocity was 7.9 ± 1.9 cm/s. Tricuspid inflow E and A wave velocities and E/A ratio were 0.52 ± 0.12 m/s, 0.42 ± 0.13 m/s, and 1.30 ± 0.27, respectively. There were no significant differences in echocardiographic data between patients who had AF lasting longer than 24 hours and those with AF lasting 24 hours or less. Anticoagulation was discontinued after demonstration of atrial contractility. No patients experienced bleeding complications during anticoagulation or thromboembolic events after cessation of anticoagulation.
CONCLUSIONS: Short-term anticoagulation may be sufficient for the prevention of thromboembolic events in patients who underwent off-pump coronary artery bypass grafting and experienced new-onset AF because right and left atrial contractility was restored early after sinus conversion.
