phonocardiograph /-kär″dē·əgraf′/ [Gk, phone, sound, kardia, heart, graphein, to record] , an electroacoustic device that produces graphic heart sound recordings using a system of microphones and associated recording equipment. One microphone is usually placed on the chest near the base of the heart. It records the timing of the aortic and pulmonary components of the second heart sound and the loudest murmurs. Another microphone is positioned on the chest over the apex of the heart. It is connected to filters that allow the recording of low-frequency sounds, such as those associated with atrial and ventricular gallops, as well as higher-frequency sounds, such as those associated with mitral regurgitation and ventricular septal defect. To ensure an accurate recording, the examiner also uses audiophones to monitor the sounds and an oscilloscope to monitor cardiac impulses. Phonocardiographs are used in the diagnosis and monitoring of heart disorders. Also called electrocardiophonograph. −phonocardiographic, adj.
