Indexed on: 30 Apr '05Published on: 30 Apr '05Published in: International Journal of Cardiology
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.To evaluate the post-exercise cardiovascular dynamics and clinical profiles in these patients.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 VO2 declines between the Fontan and RVOTR groups. Although the systolic blood pressure (SBP) decline was delayed in the RVOTR group (p < 0.01), its early decline in the Fontan group was rapid and equivalent to that in controls. In Fontan patients, BRS had a great impact on early HR decline (p < 0.05) and early VO2 decline was determined by peak VO2, age and cardiac index (p < 0.05-0.001). TCPC and lower BRS were the main determinants of the slower SBP decline (p < 0.05). In another study of repeated paired exercise tests before and after Fontan operation, post-exercise SBP decline became greater after the operation (p < 0.07).In the Fontan group, post-exercise HR and VO2 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.