Late occurrence of atrial arrhythmias after the simple left atrial procedure for chronic atrial fibrillation in mitral valve surgery.

Background: We postulated that chronic atrial fibrillation (AF) associated with mitral valve disease originated from the distended left atrium and is maintained by itself. We had performed a simple left atrial procedure for the elimination of chronic AF associated with mitral valve disease in patients from 1993 to 1998. This paper evaluated the long-term results of the simple left atrial procedure after more than 10 years, and discussed the late occurrence of atrial arrhythmias in relation to the left atrial procedure.

Methods: Fifty-two patients were examined after the simple left atrial procedure concomitant with mitral valve surgery retrospectively. We divided the patients into two groups with or without the elimination of AF (AF group and non-AF group). The disappearance of AF was estimated by electrocardiography, and atrial function was estimated by transthoracic echocardiography. The elimination of chronic AF and the recovery of atrial systolic function after surgery were evaluated during more than 10 years of follow-up.

Results: In a total of 702.5 patient-years of follow-up (range, 11.3 to 16.1 years; mean, 13.5 ± 3.5 years), AF disappeared in 73% of the patients (38 of 52) at 5 years and in 69% of the patients (36 of 52) at 10 years after the simple left atrial procedure. Among the preoperative and intraoperative variables, a long duration of AF was the only predictive factor for late recurrences of AF (p < 0.05). In the sinus rhythm group, 2 of 36 patients remained in left atrial tachycardia. The final success rate in elimination of AF and atrial tachycardia was 34 of 52 patients (65.3%) at 10 years. An atrial kick was detected in 60% of patients across the mitral valve and in 100% of patients across the tricuspid valve by transthoracic echocardiography.

Conclusions: The simple left atrial procedure could terminate chronic AF associated with mitral valve disease and maintain sinus rhythm for more than 10 years in 65% of chronic AF patients. Left atrial tachycardia was a troublesome complication after cryoablation toward mitral valvular annulus. This study shows the long-term results and problems of the simple left atrial procedure for more than 10 years of follow-up.