A phonocardiogram is a recording of the heart sounds and murmurs. The instrument used to make this recording is called the phonocardiograph. The recording of all the heart sounds during a cardiac cycle is termed to as phonocardiography.
Phonocardiogram eliminates the subjective interpretation of the heart sounds and makes it possible to evaluate them with respect to the electric and the mechanical events in the cardiac cycle.
Other related variables may also be recorded simultaneously with phonocardiogram during the clinical evaluation of a patient. These variables include ECG, carotid arterial pulse, apexcardiogram and jugular venous pulse. The indirect carotid, jugular venous and apexcardiogram pulses are recorded using a microphone system with a frequency response from 0.1 to 100 Hz. The cardiologist normally evaluates the results of a phonocardiograph on the basis of changes in the wave-shape and in a number of timing parameters.
Related: Key Factors to Consider in the Design and Operation of Electrocardiograph
