The first heart sound abnormalities accompanied with alteration of systolic time intervals in incipient heart failure.

A phonocardiological analysis of the first heart sound was made and systolic time intervals were measured in 40 patients (ischaemic heart disease, hypertensive heart disease, cardiomyopathies) with incipient cardiac failure (functional groups I--II according to the NYHA) with auscultatory changes of the first heart sound and in controls of randomly selected healthy persons or patients in whom cardiopulmonary disease was excluded. The patients in all diagnostic groups differed significantly (P less than 0.05--0.001) in practically all the phonocardiographic indicators from the controls. The most constant abnormal finding was a pathological split of the first heart sound which may be divided into three phonocardiographic forms. Simultaneously, systolic time intervals alterations (P less than 0.02--0.001) were also found in these patients and indicated a lowered performance of the left ventricle. The results suggest that 1) a certain relation exists between systolic time intervals and the phonocardiographic pattern of the first heart sound in patients with cardiovascular diseases and those without it; 2) the modified (pathologically splitted and prolonged) first heart sound could be a sign of incipient cardiac failure.