Abstract: | Isolated partial anomalous pulmonary venous drainage (PAPVD), in contrast to atrial septal defect (ASD), does not cancel out the effects of respiration on blood flow in the right ventricle. The aim of this study was to see whether this difference could contribute to the diagnosis of PAPVD without ASD on M mode echocardiography. The diastolic dimensions of the right ventricle on expiration and inspiration were compared in 4 groups of patients aged 2 to 17 years. Group 1 comprised 6 children with PAPVD without ASD; Group 2: 10 children with PAPVD and ASD; Group 3: 11 children with isolated non-restrictive ASD, and Group 4: 10 normal children. Groups 1 and 4 were comparable with a respiratory variation of RV dimension of 10 to 29%. On the other hand, in Groups 2 and 3 the percentage variation was less than 6%. The finding of isolated RV dilatation with normal respiratory variation of its internal dimension should therefore alert the operator to the possible diagnosis of PAPVD without ASD. |