Abstract
Three directional ballistocardiogram in 31 cases of atrial septal defect was studied. These cases were featured by a marked increase in anterior H, posterior I and posterior L (occasionally M) in posteroanterior BCG, an increase in H, I, or diastolic waves in head-foot BCG, and an increase in systolic and diastolic waves in lateral BCG. Several abnormal BCG's including both severe and mild cases were demonstrated and the importance of postero-anterior BCG in the diagnosis of atrial septal defect was discussed.
