Analysis of diastolic heart sounds before and after angioplasty

The frequency spectra of diastolic heart sounds are compared before and after angioplastic surgery. Since the low-level sounds associated with partially occluded coronary arteries will be contaminated with considerable background noise, traditional FFT analysis may not produce an accurate frequency spectrum. Eigenvector methods have been selected to generate the frequency spectra because of their higher resolution, particularly in the presence of noise. In all cases a marked decrease in high frequency spectral components was observed following angioplasty.<>