title: Audibility of the fourth heart sound. A prospective, "blind" auscultatory and polygraphic investigation.
mesh_terms: D000368:Aged; D016275:Atrial Function; D003327:Coronary Disease / Q000503:physiopathology; D006325:Heart Atria / Q000503:physiopathology; D006326:Heart Auscultation; D006339:Heart Rate; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008722:Methods; D008875:Middle Aged; D010701:Phonocardiography; D013997:Time Factors; D016276:Ventricular Function