Günther K H
G Ital Cardiol. 1975;5(6):862-6.
In 53 patients with either normal hearts or with rheumatic valve disease (predominantly mitral disease), third and fourth heart sounds (S3, S4), were recorded by intracardiac phonocardiography inthe left ventricle, left atrium and/or ascending aorta. The corresponding sounds were recorded externally in less than one half of the cases only. The S3 was mostly present in the ventricle and in cases of volume overload. The S4 was found with about the same incidence in the left atrium and left ventricle, and more often in cases of pressure overload. The incidence of these sounds showed only a minimal correlation with the left ventricular diastolic pressures, while no correlation at all was found between such pressures and the time intervals P-S4 and A2-S3.