Phonocardiograms of young adult macaca mulatta

Phonocardiograms were recorded and analyzed for thirteen healthy macaca mulatta. Lead aVF electrocardiograms and phonocardiograms were recorded simultaneously. Mean values and ranges for the following parameters were analyzed: RR interval, PR interval, duration between onset of P-wave and onset of first heart sound, duration between onset of QRS and onset of first heart sound, duration of first heart sound, number of vibrations in first heart sound, duration of mechanical systole, duration of second heart sound, number of vibrations in second heart sound, duration of mechanical diastole. The first heart sound had a mean duration of 0.074 second with a mean frequency of 90 cps. The second heart sound which was lower in magnitude and duration had a mean duration of 0.038 second with a mean frequency of 94 cps. Diastolic murmurs were recorded in four animals.