Distribution of aortic mechanical prosthetic valve closure sound model parameters on the surface of the chest

Abstract

Cataloged from PDF version of article.It has been previously proposed that heart valve\ud closure sounds can be modeled by a sum of decaying sinusoids,\ud based on the hypothesis that the heart cavity, heart walls, major\ud vessels, and other structures in the chest constitute a frequency\ud selective linear acoustic system and this system is excited by the\ud rapidly decelerating valve occluder. In this study, distribution\ud of the parameters of this model for the second heart sound is\ud investigated. For this purpose, heart sounds of 10 patients who\ud have a St. Jude-type bileaflet mechanical heart valve prosthesis\ud in aortic position are recorded. Recordings are performed at 12\ud different locations on the surface of the chest. To reliably assign\ud representative parameters to each recording site, signal averaging,\ud model order selection, and a special filtration technique are\ud employed. The results of the analyses are discussed in relation to\ud the above hypothesis on the heart sound generation mechanism.\ud It is observed that site-to-site variation of frequencies of modes\ud does not exceed the accuracy limit of proposed analysis method,\ud but energies of these modes vary on the surface of the chest, and\ud as a result of statistical analysis, it appears that energy of some\ud modes are significantly different between two recording sites