The fourth heart sound in patients without demonstrable heart disease.

One hundred patients, 17 to 67 years of age, had normal hearts diagnosed on the basis of complete right and left heart catheterization and coronary cineangiography. Phonocardiograms were obtained from each patient, providing an average of 17 recordings per subject for analysis; 75/100 (75%) subjects had a recordable fourth sound; 60/75 (80%) of the latter group had an audible fourth heart sound. It is concluded that recordable and audible fourth heart sounds are common findings in subjects without catheterization evidence of cardiovascular disease.