Quantification of first heart sound frequency dynamics across the human chest wall

Abstract

Power spectral analysis has attracted attention because of its potential for non-invasive cardiac diagnosis. However, time-frequency analysis of first heart sound frequency dynamics from canine epicardium has demonstrated that cardiac vibrations are fundamentally multi-component and non-stationary, questioning the validity of power spectral techniques. In this study, we employed time-frequency transforms to characterise first heart sound frequency dynamics from 27 sites across the human thorax. In contrast to the dynamics observed epicardially, the first heart sound frequency law was dominated by quasi-stationary and impulse-like components implying that the instantaneous power and the power spectrum contain most of the diagnostic information in the first heart sound.

Haemodynamic determinants of the mitral valve closure sound: A finite element study

“…Specifically, the first component of S1 is thought to arise from the ringing of the myocardium shortly after the beginning of isovolumetric contraction. Epicardial and intraventricular measurements carried out by WOOD and BARRY (1994;1995), WOOD and FESTEN (1994) and WOOD and BUDA (1992) revealed two dominant non-stationary components of S1. There was a rapidly rising frequency in early systole thought to correspond to the vibrations of the ventricle, followed by a more stable higher-frequency component corresponding to mitral valve closure.…”

Arterial pressure changes monitoring with a new precordial noninvasive sensor

“…In contrast to the dynamics observed epicardially, Wood [ 24 ] demonstrated that heart sound frequency law was dominated by quasi-stationary and impulse-like components implying that the instantaneous power and the power spectrum contain most of the diagnostic information in heart sound.…”

Time-frequency cardiac passive acoustic localization

“…Moreover, the turbulent flow due to a regurgitation or a stenosis can cause deterministic vibrations of the vessel walls and the myocardium. When these sounds are recorded on the chest wall, they are also conditioned by the transmission characteristics of the myocardium, the lung and the thoracic tissue [1][2][3][4][5][6][7].…”

“…In these investigations, the heart sounds are acquired from certain conventional landmark points on the chest. They are then processed using coherent averaging and interpolating the acoustic energy among the cardiac sensors [1,4].…”

“…In these investigations, the heart sounds are acquired from certain conventional landmarks on the thorax. They are then processed using coherent averaging and interpolation of the acoustic energy among the cardiac sensors [3], [4]. In our previous work, we used a novel, radically different approach based on concurrent multi-sensor array measurements and "super-resolution" array processing on the PCG signals [5].…”