Improved Exercise Capacity during Single Ventricle Cycle Ergometry in Fontan Patients Post TVanscatheter Fenestration Closure

Abstract

PURPOSE: To evaluate the exercise capacity of patients that have undergone a transcatheter Fontan fenestration closure. METHODS: We evaluated 11 patients (6 males, mean age 15 yrs) pre and post closure with a standardized cycle ergometer protocol developed for patients with single ventricle physiology. The average time between the two tests was 132 days. Successful fenestration closure was accomplished in all using an Amplatzer device 8.9 ± 2.9 years post Fontan. All had suitable anatomy and hemodynamics. RESULTS: Immediately following closure during cardiac catheterization, arterial saturation increased from 91 to 95% and cardiac index decreased from 2.4 to 1.8 (L/min/m2) (p<0.05). Similar peak heart rates were achieved during both exercise tests. Rest, submaximal and peak exercise O2 saturation increased from 88, 84 and 81% to 95, 94 and 92% respectively. Peak VO2, total working capacity and exercise duration increased by 7%, 17% and 11% respectively (p<0.005, p<0.05).TableCONCLUSION: O2 saturation improves throughout exercise after transcatheter fenestration closure in Fontan patients resulting in an increased aerobic and exercise capacity. These results indicate that during dynamic exercise, improved oxygen saturation increases oxygen uptake and more than compensates for the restricted resting cardiac output obtained immediately after fenestration closure with the Amplatzer device.