EARLY AND INTERMEDIATE RESULTS OF THE FONTAN PROCEDURE AT MODERATELY HIGH-ALTITUDE

At higher elevations, alveolar hypoxia increases pulmonary vascular re sistance and may limit the cardiac output of individuals without a sub pulmonary ventricle. Thus, we reviewed the outcome of definitive palli ation for tricuspid atresia and other forms of single ventricle in 60 consecutive Fontan patients Living at a mean elevation of 1,370 m (ran ge, 910 to 2,130 m). There were four early deaths (6.7%; 70% confidenc e limits, 4.1% to 10.7%) and six late deaths. Kaplan-Meier actuarial s urvival (a standard error) is 79.6% +/- 8.2% at 5 years. Survival was significantly decreased in patients with a preoperative mean pulmonary arterial pressure greater than or equal to 15 mm Hg unless the Fontan procedure was performed with a residual fenestration. Exercise tolera nce was significantly worse at higher elevations in a subgroup of pati ents who have traveled to altitudes of 1,680 to 3,350 m. We conclude t hat the early and intermediate results of the Fontan procedure at mode rately high altitude are similar to results reported at sea level. How ever, exercise tolerance may be impaired at higher elevations in many patients.