[Assessment of long-term systemic ventricular function after the surgical repair in patients with atrioventricular...

Long-term systemic ventricular function at rest and during supine bicycle exercise was studied in 12 patients with atrioventricular discordance (AVD group) using multigated radionuclide blood pool imaging. For comparison, similar measurements were made in eight children (control group). The mean age at the exercise test was 12.3 years in AVD group and was 14.8 years in the control group. In AVD group, ages at the operation ranged from three to 21 years (mean 12.3 years), and the exercise test was performed from one to 9.8 years after the operation (mean 5.3 years). The operative procedures in AVD group consisted of closure of the ventricular septal defect in 11 patients, extracardiac conduit between the left ventricle and the pulmonary artery in nine patients, postero-lateral left ventricular outflow reconstruction in two patients, tricuspid annuloplasty in one patient, and tricuspid valve replacement in one patient. Exercise tolerance of AVD group was less than that of the control group. Heart rate and blood pressure were significantly increased during exercise in both groups. In the control group, end-diastolic count index (EDCI) (= end-diastolic volume) remained unchanged and end-systolic count index (ESCI) (= end-systolic volume) decreased during exercise. In contrast, both EDCI and ESCI were decreased in AVD group. As a consequence, systemic right ventricular ejection fraction (RVEF) increased during exercise in the control group, but remained unchanged in AVD group. Although stroke count index (SCI) (= stroke volume index) did not increased during exercise in AVD group, output count index (OCI) (= cardiac index) increased with the increase of heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)