BACKGROUND: Several studies suggest that the superior transseptal approach to mitral valve surgery leads to sinus node dysfunction. The clinical consequences are not known.

METHODS: Consecutive patients undergoing surgery for mitral valve disease from November 16, 1994 through January 26, 2004 were retrospectively evaluated. The surgeons used either the superior transseptal (group A) or left atrial approach (group B). The risk of pacemaker implantation associated with the superior transseptal approach as compared with the left atrial approach was estimated using the multivariate Cox regression analysis to adjust for possible confounders.

RESULTS: We included 577 patients, 150 in group A and 427 in group B. Forty-four patients had a pacemaker implanted after the surgery; 17 in group A and 27 in group B (p = 0.010). The superior transseptal approach was an independent risk factor of pacemaker implantation in multivariate analysis (hazard ratio 2.2 [1.2 to 4.1], p = 0.014). Nineteen patients had a pacemaker implanted because of sinus node dysfunction; 9 in group A and 10 in group B (p = 0.017). Group A was an independent predictor of pacemaker implantation because of sinus node dysfunction in bivariate analyses. The risk of pacemaker implantation because of atrioventricular conduction disturbances was not different between the groups (p = 0.178).

CONCLUSIONS: The superior transseptal approach has a higher risk of clinically significant sinus node dysfunction than the left atrial approach.