Abstract
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 murmur 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.