Sound Spectrographic Diagnosis of Aortic Ball Variance

Abstract

Abnormalities in the silastic poppets of cardiac valve prostheses have been detected with increasing frequency. Ball variance can cause serious mechanical dysfunction of the prosthesis and can result in sudden death. Contour sound spectrograms were recorded on 12 patients with ball variance confirmed by operation and 25 controls. In ball variance the frequency of the aortic opening sound at the second right intercostal space was decreased, with the peak frequency recorded being below 1,300 cycles/sec in 11 of the 12 patients. The peak frequency was greater than 1,300 cycles/sec in 24 of the 25 control patients. The remaining patient had peak frequencies in both the normal and abnormal range. The diagnosis of aortic ball variance in patients with triple valve replacement remains difficult because of the nearly synchronous tricuspid closing and aortic opening sounds. The sound spectrographic findings have been the most reliable objective evidence of ball variance in patients with Starr-Edwards aortic prostheses of the Model 1000 series.

Systolic Time Intervals, Phonocardiograms and Sound Spectrograms in Patients with Starr-Edwards Aortic Valve Prostheses

“…Hylen el at. [9] measured, in cases without ball variance, a peak frequency of the aortic opening sound in the second right intercostal space above 1300 Hz. We found a peak frequency of the aortic opening sound below 1300 Hz in 7 cases, 1 with the model 1200 prosthesis and the other 6 with the model 1260 prosthesis.…”

“…Since the introduction of prosthetic ball valves in the surgical treat ment of valvular heart disease, ball variance has been reported in a sub stantial number of patients [8][9][10]13]. Left untreated, this mechanical dysfunction can result in sudden death.…”

“…A method for detecting dysfunction of the valve prosthesis relies on comparing the intensity of the prosthetic aortic opening sound with that of the closing sound (AO/AC ratio) on the phonocardiogram [8]. Hylen et al have also introduced a sound spectrographic method to improve the accuracy of diagnosis of ball variance [9,10]. However, not only prosthetic valvular dysfunction but also de pressed left ventricular function can result in a decreased AO/AC ratio and reduced peak frequency on sound spectrograms [3,4].…”

Sound Spectroanalytic Diagnosis of Malfunctioning Prosthetic Heart Valve

“…The impact sounds of occluder and struts or valve seat may be different according to the valve structure and may be altered by ball variance or interposition of other substances such as thrombus and tissues. Hylen et al (1969) stated that in ball variance of aortic prosthesis, the high frequency components of the valvular sounds, which were difficult to detect by means of phonocardiography, fell off and the peak frequency of AOS fell below 1300 Hz in 11 cases out of 12 cases of ball variance. Kingsley (1972) and Gordon et al (1974) also reported the detection of malfunctioning aortic prosthesis using an octave hand-analyzer and emphasized the usefulness of sound spectroanalysis.…”

Genesis of the Mechanical Heart Valves' Ultrasonic Closing Clicks

“…Hylen et al reported spectral analysis of the clicks in 1969 [1]. Much research was reported thereafter.…”