Comparative time domain modelling of natural heart valve and mechanical heart valve sounds

The mitral PCG (phonocardiogram) sounds of a patient who has a mechanical valve prosthesis is compared with PCG sounds from a control group consisting of normal subjects, with particular emphasis on the frequency variation. All heart sounds have similar distribution of resonance frequencies in the passband of the amplifier, irrespective of the heart valve, i.e. whether it is natural or prosthetic. A significant difference, however, exists between the normals´ and the patient´s PCGs as far as the distribution of energy among modes is concerned. In normal PCGs most of the energy is confined to the lowest frequency mode, whereas in the PCG from a patient with a prosthetic valve implant, the most significant component is at 274 Hz.<>