The role of auscultation in the differentiation of Fallot's tetralogy from severe pulmonary stenosis with intact ventricular septum and right-to-left interatrial shunt.

A clinical and phonocardiographic study has been made of the murmurs and heart sounds in the differentiation of Fallot's tetralogy from severe pulmonary stenosis with intact septum and right-to-left interatrial shunt. A striking difference in the behaviour of the systolic mnurlmur was found in the two conditions and this affords a new, simple bedside method of diagnosis. Important differences in the behaviour of the heart sounds were also found, but these are usually more difficult to evaluate clinically and may require special study. HE value of auscultation in the diagnosis of congenital heart disease has not been sufficiently appreciated. This paper is concerned with the importance of auscultation in the differential diagnosis between Fallot's tetralogy and severe pulmonary stenosis with intact ventricular septum and reversed interatrial shunt. Accurate diagnosis is of great importance. The Blalock-Taussig operation is contraindicated for severe pulmonary stenosis with reversed interatrial shunt, whereas it has proved to be an excellent operation for Fallot's tetralogy.1-5 The diagnosis can generally be made with a reasonable degree of accuracy from consideration of the clinical, radiological and electrocardio-graphic findings. However, it is often necessary to confirm the diagnosis by means of cardiac catheterisation and angiocardiography. Even with all available methods, certain difficulties arise as discussed elsewhere.6 Any additional, clinical differentiating sign is therefore of value and it is the purpose of this communication to present new physical signs, which will enable accurate diagnosis to be made by careful bedside auscultation. Furthermore, certain clinical and phono-714 cardiographic observations made during the study will be presented. CLINICAL MATERIAL AND METHODS All cases accepted for this study presented the common diagnostic problem of pulmonary or infun-dibular stenosis associated with central cvanosis. This combination usually resolves itself into the diagnosis of Fallot's tetralogy and severe pulmonary stenosis with reversed interatrial shunt. Pulmnonary stenosis with rare associations such as transposition of the great vessels, single ventricle and tricuspid atresia were excluded from this study. Eighteen cases of Fallot's tetralogy and six cases of severe pulmonary stenosis with intact ventricular septum form the basis of this study. All cases had central cyanosis. Cases were accepted only if cardiac catheterisation, selective angiocardiography, intravenous angiocardiography or necropsy proved (a) whether severe pulmonary valvular or infundibular stenosis was present and, (b) whether the ventricular septumn was intact or not. If the right-to-left shunt took place in the ventricle through a ventricular septal defect and overriding aorta, then Fallot's tetralogy …