Sinus node function after mitral valve surgery using the superior septal approach

Background. Sinus node function after the superior septal approach (SSA) in mitral valve surgery is controversial. We assessed sinus node function aft er this approach based on electrophysiological examinations and electrocard iographic change. Methods. Forty-six patients underwent successful mitral valve surgery via t he SSA. Preoperatively, 25 patients were in atrial fibrillation (AF), 20 we re in normal sinus rhythm (SR), and 1 patient was paced. Thirteen patients who demonstrated no sinus node dysfunction preoperatively underwent postope rative electrophysiological studies. Peripostoperative cardiac rhythm was m onitored using a portable four-lead electrocardiograph, and late cardiac rh ythm was examined using standard 12-lead electrocardiography in the outpati ent clinic. Results. Twelve of 20 patients with preoperative SR experienced early posto perative supraventricular arrhythmias, but all spontaneously recovered SR. Electrophysiological studies revealed a basic cycle length of 767 +/- 74 ms , sinoatrial conduction time of 72 +/- 34 ms, sinus node recovery time of 1 ,119 +/- 139 ms, and corrected sinus node recovery time of 349 +/- 114 ms, thus demonstrating a lack of sinus node dysfunction. During the postoperati ve period (34 +/- 24 months), 2 of the 20 patients with preoperative SR dev eloped persistent AF, and 3 of the 25 patients with preoperative AF achieve d normal SR. Conclusions. The SSA does not appear to cause longterm adverse effects on s inus node function, although temporary effects may occur. (C) 2001 by The S ociety of Thoracic Surgeons.