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Determinants of diastolic myocardial tissue Doppler velocities: influences of relaxation and preloadMyocardial tissue Doppler echocardiography (TDE) has been proposed as a tool for the assessment of diastolic function. Controversy exists regarding whether TDE measurements are influenced by preload. In this study, left ventricular volume and high-fidelity pressures were obtained in eight closed-chest dogs during intermittent caval occlusion. The time constant of isovolumic ventricular relaxation (tau) was altered with varying doses of dobutamine and esmolol. Peak early diastolic myocardial (E(m)) and transmitral (E) velocities were measured before and after preload reduction. The relative effects of changes in preload and relaxation were determined for E(m) and compared with their effects on E. The following results were observed: caval occlusion significantly decreased E (DeltaE = 16.4 +/- 3.3 cm/s, 36.6 +/- 13.7%, P < 0.01) and E(m) (DeltaE(m) = 1. 3 +/- 0.4 cm/s, 32.5 +/- 26.1%, P < 0.01) under baseline conditions. However, preload reduction was similar for E under all lusitropic conditions (P = not significant), but these effects on E(m) decreased with worsening relaxation. At tau < 50 ms, changes in E(m) with preload reduction were significantly greater (DeltaE(m) = 2.8 +/- 0.6 cm/s) than at tau = 50-65 ms (DeltaE(m) = 1.2 +/- 0.2 cm/s) and at tau >65 ms (DeltaE(m) = 0.5 +/- 0.1 cm/s, P < 0.05). We concluded that TDE E(m) is preload dependent. However, this effect decreases with worsening relaxation.
Document ID
20040112641
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Firstenberg, M. S.
(The Cleveland Clinic Foundation Cleveland, Ohio 44195, United States)
Greenberg, N. L.
Main, M. L.
Drinko, J. K.
Odabashian, J. A.
Thomas, J. D.
Garcia, M. J.
Date Acquired
August 21, 2013
Publication Date
January 1, 2001
Publication Information
Publication: Journal of applied physiology (Bethesda, Md. : 1985)
Volume: 90
Issue: 1
ISSN: 8750-7587
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: RO1 HL-56688-01A1
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Cardiopulmonary
Non-NASA Center

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