Initial low frequency vibrations of the first heart sound.
D001281:Atrial Fibrillation / Q000503:physiopathology; D001769:Blood; D004562:Electrocardiography; D006321:Heart / Q000503:physiopathology; D006326:Heart Auscultation; D006350:Heart Valve Prosthesis; D006801:Humans; D007702:Kinetocardiography; D008944:Mitral Valve Insufficiency / Q000503:physiopathology / Q000601:surgery; D010701:Phonocardiography; D014262:Tricuspid Valve Insufficiency / Q000601:surgery; D014732:Vibration