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Color M-mode Doppler flow propagation velocity is a preload insensitive index of left ventricular relaxation: animal and human validationOBJECTIVES: To determine the effect of preload in color M-mode Doppler flow propagation velocity (v(p)). BACKGROUND: The interpretation of Doppler filling patterns is limited by confounding effects of left ventricular (LV) relaxation and preload. Color M-mode v(p) has been proposed as a new index of LV relaxation. METHODS: We studied four dogs before and during inferior caval (IVC) occlusion at five different inotropic stages and 14 patients before and during partial cardiopulmonary bypass. Left ventricular (LV) end-diastolic volumes (LV-EDV), the time constant of isovolumic relaxation (tau), left atrial (LA) pre-A and LV end-diastolic pressures (LV-EDP) were measured. Peak velocity during early filling (E) and v(p) were extracted by digital analysis of color M-mode Doppler images. RESULTS: In both animals and humans, LV-EDV and LV-EDP decreased significantly from baseline to IVC occlusion (both p < 0.001). Peak early filling (E) velocity decreased in animals from 56 +/- 21 to 42 +/- 17 cm/s (p < 0.001) without change in v(p) (from 35 +/- 15 to 35 +/- 16, p = 0.99). Results were similar in humans (from 69 +/- 15 to 53 +/- 22 cm/s, p < 0.001, and 37 +/- 12 to 34 +/- 16, p = 0.30). In both species, there was a strong correlation between LV relaxation (tau) and v(p) (r = 0.78, p < 0.001, r = 0.86, p < 0.001). CONCLUSIONS: Our results indicate that color M-mode Doppler v(p) is not affected by preload alterations and confirms that LV relaxation is its main physiologic determinant in both animals during varying lusitropic conditions and in humans with heart disease.
Document ID
20040141700
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Garcia, M. J.
(Cleveland Clinic Foundation Ohio 44195, United States)
Smedira, N. G.
Greenberg, N. L.
Main, M.
Firstenberg, M. S.
Odabashian, J.
Thomas, J. D.
Date Acquired
August 22, 2013
Publication Date
January 1, 2000
Publication Information
Publication: Journal of the American College of Cardiology
Volume: 35
Issue: 1
ISSN: 0735-1097
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: RO1 HL56688-01A1
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Discipline Cardiopulmonary
NASA Program Biomedical Research and Countermeasures

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