Objective: The incidence of sinus conversion in the enlarged left atrium after atrial fibrillation surgery is reported to be low. The purpose of the current study was to investigate the effects of atrial fibrillation surgery on mitral valve disease associated with a giant left atrium (GLA).
Method: From July of 1997 to February of 2002, 188 patients received mitral valve and atrial fibrillation surgery. The patients were placed in either GLA group (n = 94), or NGLA group (n = 94), based on LA size. The presence and onset of sinus rhythm and the incidence and velocity of transmitral A waves were monitored during the early postoperative period and throughout the follow up period of 42 months.
Results: The onset of postoperative sinus rhythm was slightly earlier in the NGLA group than in the GLA group at 1.3+/-0.4 days versus 3.1+/-1.2 days, respectively, (P = 0.008). The sinus conversion rates in the GLA and the NGLA groups were 91.5 and 97.9% in the early postoperative period, and 94.7 and 95.7% at 6 months after surgery, respectively. A wave appearance rates in the early postoperative period in the GLA and the NGLA groups were 62.2 and 71.7%, and continued to improve over time to 94 and 95% by 36 months, respectively. Peak A wave velocities in the early postoperative period in GLA and NGLA groups were 67.4+/-34.0 and 61.1+/-29.5 cm/s without significant change during the follow up.
Conclusion: The results suggest that atrial fibrillation surgery is effective at inducing sinus rhythm and restoring left atrial contractile function after concomitant mitral valve surgery regardless of LA size.