BACKGROUND: Atrial fibrillation is common after mitral valve surgery. We do not know the incidence of atrial tachycardia and how it depends on the surgical approach used.

METHODS: The subjects of the study were 213 consecutive patients who had surgery for mitral valve disease from January 1, 2001, through January 26, 2004. The surgeons used either the superior transseptal approach (69 patients, group A) or left atrial approach (144 patients, group B). An investigator, blinded for the approach used, analyzed all 12-lead electrocardiograms taken during the admission after the operation. The data were analyzed using the Cox regression analysis as time from the operation until documentation of atrial tachycardia or atrial fibrillation on a 12-lead electrocardiogram. Hazard ratio (95% confidence interval) is reported.

RESULTS: The superior transseptal approach (2.0 [1.1 to 3.5], p = 0.023), age 60 years or more (2.3 [1.2 to 4.6], p = 0.015), and male sex (2.6 [1.3 to 5.2], p = 0.007) were independent predictors of atrial tachycardia. Age 60 years or more was the only independent predictor of atrial fibrillation (2.0 [1.2 to 3.3], p = 0.007). Although atrial tachycardia was less frequent than atrial fibrillation in group B (p < 0.001), atrial tachycardia was as common as atrial fibrillation in group A (p = 0.149).

CONCLUSIONS: The superior transseptal approach has a higher risk of atrial tachycardia than the left atrial approach. Atrial tachycardia has different predictors than atrial fibrillation and constitutes a significant problem, especially after the superior transseptal approach. These results emphasize the need to distinguish between atrial tachycardia and atrial fibrillation-two entities with different pathophysiology, therapy, and also epidemiology.