The object of this proposal is to explore the usefulness of measurement of the frequency of the closure sounds of porcine bioprosthetic valves to determine if early and subclinical degeneration can be detected by this non-invasive method. The specific goal of the requested continuation of this investigation is to determine if changes of the frequency of the closure sound of bioprosthetic valves can be detected before clinical evidence of degeneration becomes apparent. It is important to know how soon changes of the frequency precede clinical evidence of degenerative changes. We have shown that the dominant frequency of heart sounds in patients with spontaneously degenerated porcine bioprosthetic valves is abnormally elevated when the degenerated valves are stiffened due to calcium or fibrosis. We also showed that the frequency content of the closure sounds of bioprosthetic valves is higher after five years of insertion than during the first 18 months. This suggests that stiffening progressively occurred. These observations were predictable and understandable on the basis that stiffening of a membrane increases the natural frequency with which it vibrates. Now that we know that the frequency of the closure sound of bioprosthetic valves increases with the duration of insertion, it would be useful for practical application of the method, to know how changes of the frequency relate to changes of the clinical status of individual patients, and to what extent measurable changes of frequency are predictive of future clinical degeneration of the bioprosthetic valve.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
2R01HL023669-06
Application #
3337350
Study Section
Surgery and Bioengineering Study Section (SB)
Project Start
1979-04-01
Project End
1988-03-31
Budget Start
1985-04-01
Budget End
1986-03-31
Support Year
6
Fiscal Year
1985
Total Cost
Indirect Cost
Name
Henry Ford Health System
Department
Type
DUNS #
City
Detroit
State
MI
Country
United States
Zip Code
48202
Durand, L G; Guo, Z; Sabbah, H N et al. (1993) Comparison of spectral techniques for computer-assisted classification of spectra of heart sounds in patients with porcine bioprosthetic valves. Med Biol Eng Comput 31:229-36
Bell, D R; Sabbah, H N; Stein, P D (1989) Profiles of velocity in coronary arteries of dogs indicate lower shear rate along inner arterial curvature. Arteriosclerosis 9:167-75
Stein, P D; Sabbah, H N; Flynn, M (1989) Very high speed (2,000 frames s-1) cine angiography for evaluation of instantaneous left ventricular function. J Biomech 22:755-9
Leeper Jr, K V; Popovich Jr, J; Lesser, B A et al. (1988) Treatment of massive acute pulmonary embolism. The use of low doses of intrapulmonary arterial streptokinase combined with full doses of systemic heparin. Chest 93:234-40
Sabbah, H N; Brymer, J F; Gheorghiade, M et al. (1988) Left ventricular function after successful percutaneous transluminal coronary angioplasty for postinfarction angina pectoris. Am J Cardiol 62:358-62
Khaja, F; Sabbah, H G; Brymer, J F et al. (1988) Influence of coronary collaterals on left ventricular function in patients undergoing coronary angioplasty. Am Heart J 116:1174-80
Rival, J; Riddle, J M; Stein, P D (1987) Effects of chronic smoking on platelet function. Thromb Res 45:75-85
Hamid, M S; Sabbah, H N; Stein, P D (1987) Vibrational analysis of bioprosthetic heart valve leaflets using numerical models: effects of leaflet stiffening, calcification, and perforation. Circ Res 61:687-94
Sabbah, H N; Hamid, M S; Stein, P D (1986) Mechanical stresses on closed cusps of porcine bioprosthetic valves: correlation with sites of calcification. Ann Thorac Surg 42:93-6
Sabbah, H N; Marzilli, M; Liu, Z Q et al. (1986) Relation of intramyocardial pressure to coronary pressure at zero flow. Clin Exp Pharmacol Physiol 13:477-86

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