Left and right ventricular volume characteristics in tetralogy of Fallot and their relationship to arterial oxygen saturation and age.

Left (LV) and right ventricular (RV) volume characteristics in 43 patients with tetralogy of Fallot (TOF) undergoing no prior surgical intervention, aged 3-50 months, were evaluated. The control group consisted of 45 patients with Kawasaki disease without cardiac lesions, aged 12-82 months. The TOF patients were divided into four groups: those having arterial oxygen saturation < 80% with an age at the time of study < 18 months (group 1a) or with that > or = 18 months (group 1b), and those with arterial oxygen saturation > or = 80% with an age < 18 months (group 2a) or with that > or = 18 months (group 2b). The results were compared with those in control subjects. In group 1a, each of LV end-diastolic volume (EDV), LV ejection fraction (EF), RVEDV and RVEF was reduced. In group 1b, LVEDV, LVEF and RVEF were decreased. In groups 2a and 2b, RVEF alone was depressed. From these results, the severity of hypoxemia was an important risk factor for ventricular dysfunctions. No influence of age on the volume characteristics was found. The investigations suggested that patients with TOF having an arterial oxygen saturation < 80% are probably candidates for early surgical intervention.