Abstract

The overall objectives are (a) to introduce the new concept of systolic myocardial stiffness and test the hypothesis that end systolic myocardial stiffness in independent of end systolic stress (b) test the validity of this concept and the end systolic P-V relationship in the pathologic state. (c) establish the mechanical and hemodynamic correlates during the stable and decompensated states of LV hypertrophy induced by volume and pressure overload in conscious dogs. Serial studies will be conducted in the volume-overload model (AV fistula or aortic regurgitation) and pressure-overload models (aortic banding and perinephritic hypertension). Heart failure will be induced by superimposing a volume overload on dogs with severe aortic stenosis and compensated LV hypertrophy. LV volume calculations will be based on both the ultrasonic dimension technique and cineventriculography. More reliable assessments of myocardial function are needed for optimum timing of valve replacement in patients with chronic LV volume overload or pressure overload. These studies will provide a sound basis for the development of new myocardial function parameters, and a better understanding of the mechanisms involved in LV hypertrophy.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL034596-04
Application #
3347668
Study Section
Cardiovascular Study Section (CVA)
Project Start
1984-12-01
Project End
1990-11-30
Budget Start
1988-12-01
Budget End
1989-11-30
Support Year
4
Fiscal Year
1989
Total Cost
Indirect Cost

  Institution

Name
Brigham and Women's Hospital
Department
Type
DUNS #
071723621
City
Boston
State
MA
Country
United States
Zip Code
02115

  Publications

Mirsky, I; Aoyagi, T; Ihara, T et al. (1995) Contractile state is the major determinant of functional outcome in patients with left ventricular dysfunction treated with enalapril. Eur Heart J 16:808-17
Aoyagi, T; Pouleur, H; Van Eyll, C et al. (1993) Wall motion asynchrony is a major determinant of impaired left ventricular filling in patients with healed myocardial infarction. Am J Cardiol 72:268-72
Aoyagi, T; Fujii, A M; Flanagan, M F et al. (1993) Transition from compensated hypertrophy to intrinsic myocardial dysfunction during development of left ventricular pressure-overload hypertrophy in conscious sheep. Systolic dysfunction precedes diastolic dysfunction. Circulation 88:2415-25
Aoyagi, T; Fujii, A M; Colan, S D et al. (1992) Different responses of extent and velocity of contraction to dobutamine in conscious sheep. Am J Physiol 263:H1250-61
Aoyagi, T; Mirsky, I; Flanagan, M F et al. (1992) Myocardial function in immature and mature sheep with pressure-overload hypertrophy. Am J Physiol 262:H1036-48
Aoyagi, T; Momomura, S; Matsui, H et al. (1991) Myocardial contractility and contraction duration are unrelated in the left ventricle with moderate pressure-overload hypertrophy. Jpn Heart J 32:111-30
Parker, J D; Landzberg, J S; Bittl, J A et al. (1991) Effects of beta-adrenergic stimulation with dobutamine on isovolumic relaxation in the normal and failing human left ventricle. Circulation 84:1040-8
Mirsky, I; Pasipoularides, A (1990) Clinical assessment of diastolic function. Prog Cardiovasc Dis 32:291-318
Mirsky, I; Aoyagi, T; Crocker, V M et al. (1990) Preload dependence of fiber shortening rate in conscious dogs with left ventricular hypertrophy. J Am Coll Cardiol 15:890-9
Aoyagi, T; Fujii, A M; Gelpi, R J et al. (1990) Application of the systolic stiffness concept to assess myocardial function in developing hypertension. Jpn Heart J 31:71-85

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