Post-exercise heart rate, blood pressure and oxygen uptake dynamics in pediatric patients with Fontan circulation Comparison with patients after right ventricular outflow tract reconstruction

Abstract Background Post-exercise heart rate (HR) and oxygen uptake (V˙O 2 ) recover more slowly in patients with the Fontan circulation, but little is known about the determinants of the delayed recovery. Purpose To evaluate the post-exercise cardiovascular dynamics and clinical profiles in these patients. Methods and results We studied 51 Fontan patients (14±4 years) (atriopulmonary connection, APC=18 and total cavopulmonary connection, TCPC=33) and compared the results with 34 patients after right ventricular outflow tract reconstruction (RVOTR) with identical exercise capacity and arterial baroreflex sensitivity (BRS) (15±4 years) and with 26 controls (14±4 years). There were no differences in post-exercise HR or V˙O 2 declines between the Fontan and RVOTR groups. Although the systolic blood pressure (SBP) decline was delayed in the RVOTR group ( p p 2 decline was determined by peak V˙O 2 , age and cardiac index ( p p p Conclusions In the Fontan group, post-exercise HR and V˙O 2 declines are markedly delayed and are determined by cardiac vagal nervous activity, exercise capacity and age, respectively. Despite identical impaired hemodynamics and exercise capacity, post-exercise SBP decline is greater in the Fontan group, especially after APC, than in the RVOTR patients.