EARLY AND LATE ATRIAL DYSRHYTHMIAS AFTER MODIFIED FONTAN OPERATION - IMPLICATIONS OF PREOPERATIVE HEMODYNAMICS AND TYPE OF OPERATION (ATRIOPULMONARY VS TOTAL CAVOPULMONARY CONNECTION)

Between October 1986 and March 1992, occurrence of supraventricular ta chycardia and sinus node dysfunction was investigated pre- and postope ratively by serial ECG and Holter monitors in 63 consecutive patients with univentricular circulation after modified Fontan operation (total cavopulmonary connection 39 patients, atriopulmonary connection 24 pa tients). Mean age at operation was 7.2 (0.1-20.3) years. Of the 63 pat ients, 14 (22 %) had early (< 14 d) supraventricular tachycardia or si nus node dysfunction, which was not related to the type of operation. None of nine patients with a preoperative mean right atrial pressure l ess-than-or-equal-to 2.5 mm Hg had early supraventricular tachycardia or sinus node dysfunction, in contrast to 16/54 patients (30 %) with a preoperative mean right atrial pressure greater-than-or-equal-to 2.5 mm Hg. 6/63 patients died during the early (< 14 d) postoperative peri od. In only one child death was related to a dysrhythmia (junctional e ctopic tachycardia). During a mean follow-up of 2.5 years, 12 patients (21 %) had late supraventricular tachycardia or sinus node dysfunctio n. Early supraventricular tachycardia/sinus node dysfunction was a pre dictor of late atrial dysrhythmias, as it occurred in eight of the sur viving 14 patients with early dysrhythmias, in contrast to four childr en without early atrial dysrhythmias (p < 0.001). After creation of an atriopulmonary connection, 10/22 patients (45 %) had late supraventri cular tachycardia/sinus node dysfunction, but only 2/35 patients (6 %) with a total cavopulmonary connection had late atrial dysrhythmias (p < 0.001). Conclusions: Early atrial dysrhythmias after the Fontan ope ration were related to preoperative hemodynamics. Early supraventricul ar tachycardia/sinus node dysfunction and the atriopulmonary type of F ontan connection were significant risk factors for late atrial dysrhyt hmias.