The size of the orifices of the pulmonary trunk and aorta in atrial septal defect, ventricular septal defect, patent ductus arteriosus and tetralogy of Fallot.

To estimate the influence of the pulmonary (Qp) and systemic (Qs) blood flow on the size of the orifices of the pulmonary trunk (PT) and aorta (AO), the early systolic diameters of the orifices of both great vessels were measured from the cineangiocardiograms in 33 children with ventricular septal defect (VSD), 30 with atrial septal defect of the secundum type (ASD), 24 with patent ductus arteriosus (PDA), and 29 with tetralogy of Fallot (TF). They were compared to 35 normal children (N). An excellent linear correlation between the ratio of squared diameters of PT and AO orifices (PT2/AO2) and Qp/Qs was found in patients with ASD (r = 0.80, P less than 0.001), good in VSD group (r = 0.57, P less than 0.001), weak in TF (r = 0.36, P less than 0.028) and no correlation in the PDA group. PT2/AO2 was significantly greater in ASD (2.38:1 +/- 0.56) and VSD (1.76:1 +/- 0.44), and smaller in TF (0.20:1 +/- 0.10) (P less than 0.005). There were no significant differences between PDA (1.33:1 +/- 0.25) and N group (1.22:1 +/- 0.17) (P greater than 0.05). The size of PT2 per 100 cm of body height was increased in ASD, VSD and PDA, and decreased in TF (P less than 0.005). The corresponding value for AO2 was increased in PDA and TF (P less than 0.005).