BEAT-TO-BEAT VARIATION IN THE SPLIT SECOND HEART SOUND.
D001021:Aortic Valve; D006347:Heart Sounds; D006801:Humans; D010701:Phonocardiography; D011664:Pulmonary Valve; D012119:Respiration
AORTIC VALVE; PHONOCARDIOGRAPHY; PULMONARY VALVE; RESPIRATION