[Phonocardiographic findings of atypical patent ductus arteriosus with pulmonary hypertension].

Among 71 patients with proved patent ductus arteriosus (PDA) as a sole anomaly, 13 were diagnosed as having "atypical PDA" because of a lack of a continuous murmur. Of these, 10 had find-pulmonary hypertension and were the materials of the present study, in which the phonocardiographic findings were correlated with the findings by other techniques including pulsed Doppler echocardiography. Six cases with equal pulmonary arterial and aortic pressures showed a diastolic murmur alone. The murmur started with the pulmonic component of the second heart sound and continued throughout diastole. All cases showed inspiratory augmentation or presystolic accentuation of the diastolic murmur. Pulsed Doppler echocardiograms disclosed that the murmur was produced by pulmonary regurgitation in five of six cases and by a left-to-right shunt via the ductus plus pulmonary regurgitation in one case. A to-and-fro murmur was observed in three cases. Pulmonary artery pressure was significantly lower than that of the systemic artery in two of three cases. These hemodynamic findings and pulsed Doppler echocardiograms indicated that the murmur of the two cases was produced by both a left-to-right shunt through the ductus and pulmonary regurgitation. A systolic murmur only was seen in one case and the cause of this murmur was not clear. In four of five cases with grade IV and V murmur, division or plugging of the ductus was performed with uneventful clinical course in three and sudden death in one. On the other hand, four of five cases with grade II and III murmur showed Eisenmenger reaction and the surgery was not attempted. The second heart sound showed normal splitting in eight cases, abnormally wide splitting in one case and was single in one case.