先天性心疾患の心音図学的研究

第1編 術前・後後の心音図

抄録

Phonocardiographic studies were made on 122 cases of Congenital Heart Diseases (CHD), consisting of 40 cases of Atrial Septal Defect (ASD), 35 of Ventricular Septal Defect (VSD), 21 of Patent Ductus Arteriosus (PDA), 21 of Tetralogy of Fallot (TOF) and 5 of Pulmonary Stenosis (PS). The following results were obtained.
1. Intensity ratio of the first heart sound (I sound) was increased in ASD and TOF, rather decreased in PS. In every disease, intensity ratio was diminished after intracardiac operation.
2. Splitting interval of I sound (Ia-Ib interval) was within normal limits and was considered of little clinical significance.
3. Ib/Ia ratio diminished after corrective surgery.
4. Q-I interval was slightly prolonged in all diseases except PS and was prolonged after corrective surgery in ASD and TOF (Blalock-Taussig's operation),
5. Pulmonary ejection sound was found in 47.5% of ASD, 57.1% of VSD and 20% of PS. Q-Ejection sound (Q-E) interval was 0.12 sec. in ASD, 0.11 sec. in VSD and 0.10 sec. in PS on an average. Ejection sound appeared at a higher rate in ASD with pulmonary hypertension (PH) or high right ventricular pressure (RV-press.), in VSD with high RV-press. or in mild PS, being or diminished after corrective surgery. Aortic ejection sound appeared in 47.6% of TOF. Q-E interval was 0.11 sec. in TOF on an average. It appeared independently of RV-press. and remained after surgical correction.
6. Splitting of the second heart sound (IIA-IIP interval) was within normal limits in VSD and PDA, and was prolonged in ASD, TOF and PS. It was shortened after corrective surgery in all case. It was roughly proportional to shunt ratio in ASD and showed a tendency to be prolonged in ASD with PS. In PS, the higher RV-press., the more longer the IIA-IIP interval.
7. IIP/IIA ratio was higher in ASD, and lower in VSD, TOF and PS. After corrective surgery, it was increased in PS and decreased in the other diseases. 70.4% of ASD with IIP/IIA ratio higher than 1.0, had shunt ratio higher than 50%. In ASD with PS, the amplitude of IIP was smaller and in ASD with PH, it was larger. In VSD with PH, it was larger. Mild TOF showed IIP. IIP of TOF appeared frequently following Blalock-Taussig's operation. In occasional severe cases of PS, amplitude of IIP was smaller.
8. Frequency in appearance of the third heart sound (III sound) was higher in VSD than ASD. No changes were found after corrective surgery in all diseases. In TOF, III sound appeared infrequently, but following Blalock-Taussig's operation it was found frequently. There was no appearance of III sound in PS.
9. Eddy sound showed a tendency to be appeared in PDA with higher shunt ratio and disappeared after corrective surgery.
10. Pattern of systolic murmur (SM) showed Plateau type or Crescendo-Decrescendo (Cres. Decres.) type in most ASD and showed Cres. Decres. type in most ASD with PS. In ASD with large shunt ratio and high RV-press., there were a tendency to be showed Cres. Decres. type. It disappeared or changed to Plateau type after corrective surgery. Plateau type showed common in small VSD and Cres. type showed common in large VSD. It disappeared or changed to Plateau type after corrective surgery. Pattern of SM in most TOF showed Plateau type. In two of them, no murmur found, aud in three cases after Blalock-Taussig's operation, continuous murmur was showed. In PS, murmur showed Plateau type after corrective surgery.
11. Peak of SM shifted backward in ASD with sharp pressure gradient and there was more delayed the peak of SM in cases of ASD with PS. Peak of SM had no significant relation with shunt ratio or PA-press., but if defect was large, it showed a tendency to shift forward. In VSD, peak of SM stood more backward than in ASD, and if complicated with PH, it stood early in systole. After corrective surgery, it stood in mid-systole.