Comparison of late post-operative cardiopulmonary responses in the Fontan versus ventricular septation for double-inlet left ventricular repair.

Ventricular septation (VS) and the Fontan procedure are alternatives for definitive repair in patients with double-inlet left ventricle; although VS is theoretically preferable, the current preference in practice is the Fontan procedure. However, the long-term outcomes of both procedures remain unclear. To address this issue, cardiopulmonary responses during exercise were measured in patients with double-inlet left ventricle, and the impact of the type of procedure performed, Fontan or VS, on long-term exercise capacity and late postoperative clinical profiles was assessed. Fourteen post-Fontan patients (mean age 17+/-6 years) and 13 VS patients (mean age 19+/-4 years) underwent exercise testing. Of the 13 VS patients, 5 required atrioventricular valve replacement (AVVR), and 7 required pacemaker implantation. Although no difference in peak oxygen uptake was found between the VS and Fontan patients, peak oxygen uptake was higher in VS patients without AVVR (30+/-8 ml/kg/min) than in VS patients with AVVR (19+/-1 ml/kg/min) and Fontan patients (22+/-6 ml/kg/min) (p<0.01). There was no significant difference in peak oxygen uptake between the VS patients with and without pacemaker implantation (p=0.09). The clinical profiles of the VS and Fontan patients were similar in terms of medication and freedom from tachyarrhythmias or reoperations during the follow-up period. In conclusion, the data suggest that VS without AVVR provides excellent future exercise capacity in selected patients with double-inlet left ventricle.