[Superior septal approach for mitral valve surgery].

The superior septal approach (SSA) for mitral valve surgery is a useful approach, but it may bring about demage to sinus node function or an atrial electrical vulnerable condition because the sinus node artery is divided and a large portion of both atria is incised. From April 1992 to December 1994, we used this approach in 17 patients. There was no hospital death and none had perioperative complications associated with the approach. All nine patients in sinus rhythm preoperatively returned to sinus rhythm before discharge from the hospital and remained so at late follow-up. Five of 9 patients with sinus rhythm had electrophysiological examination preoperatively and all 9 patients had the examination postoperatively. Atrial vulnerability was not deteriorated after the operation in all cases. Under pharmacologic autonomic blockade, sinoatrial conduction time (SACT), sinus node recovery time (SNRT) after overdrive atrial pacing, and corrected SNRT were 73 +/- 35 msec, 1142 +/- 168 msec, and 365 +/- 122 msec, respectively. All these values were with in normal range and these were no significant differences between before and after the operation. All patients with sinus rhythm had 3 minutes of Bruce stage 1 exercise 9 months after the operation. The heart rate response to the exercise was as good as in healthy control people. In conclusion, as far as the midterm postoperative period, the effect of SSA on sinus node function and atrial vulnerability was acceptable.