The Diastolic Murmur of Atrial Septal Defects as Detected by Intracardiac Phonocardiography

Abstract

Intracardiac phonocardiography was performed in 18 patients with the secundum type of atrial septal defect. In eight patients a delayed diastolic murmur was recorded in the inflow tract of the right ventricle and was probably due to the increased flow through the tricuspid valve; the murmur was audible at external auscultation in five of the patients. In 13 patients a diastolic murmur was recorded in the right atrium; eight patients had an early diastolic murmur, two patients had a delayed diastolic murmur, and the remaining three patients had both kinds of murmurs. The early diastolic murmur did not correspond in time to the murmur found in the right ventricle and was probably due to the flow through the defect. The delayed diastolic murmur could be due either to the flow through the tricuspid valve or through the defect. None of the atrial diastolic murmurs were audible at external auscultation.