The systolic component of the presystolic murmur.
D000293:Adolescent; D000328:Adult; D001281:Atrial Fibrillation / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008946:Mitral Valve Stenosis / Q000503:physiopathology*; D010701:Phonocardiography