The Genesis of the Opening Snap in Mitral Stenosis: Correlations between Spectral Analysis and Echocardiographic Data

Abstract

In an effort to clarify the genesis of the opening snap (OS) of mitral stenosis (MS), the frequency versus amplitude spectra of OS of 30 patients were obtained using the FFT algorithm together with mono- and twodimensional échocardiographie parameters. Each echo parameter was correlated with the relative energy contained in each of the 20-Hz bands in which the normalized average spectrum of OS of each subject was divided. Out of these echo parameters, only left atrial volume, mitral valve area, septal and posterior left ventricular diastolic slopes showed significant correlations with the phonocardiographic signal. Besides the role of the valvular apparatus, the size of the left atrium seems to be the most important factor. The left atrium with the blood it contains appears to represent the mass of a mass-spring system which is maximally decelerated rendering manifest the forces generating the vibrations when the stenotic valve suddenly blocks the blood flow.

A mass-spring model hypothesis of the genesis of the physiological third heart sound.

“…This area was then normalized with respect to the total area of the curve of the entire spectrum. 15) c) Echocardiographic parameters The echocardiographic mono-and two-dimensional studies were performed using a commercially available sector scanner. Patients were examined during held expiration and the heart was visualized using parasternal and apical transducer locations.…”

Clinical Value of the Pitch of the Third Heart Sound in Ischemic Heart Disease

“…For each of these bands, the area under the curve of the spectrum was calculated using a trapezoi dal technique and assumed as an index of the energy contained in the band. This area was normalized with respect to the total area of the curve of the entire spectrum [12][13][14],…”