Document Detail

Impact of arterial load and loading sequence on left ventricular tissue velocities in humans.
MedLine Citation:
PMID:  17936156     Owner:  NLM     Status:  MEDLINE    
OBJECTIVES: The aim of this study was to examine the relationship between individual components of left ventricular (LV) afterload and tissue Doppler echocardiography (TDE) velocities in humans. BACKGROUND: Acute increases in afterload slow diastolic relaxation as assessed invasively, yet little is known about chronic effects of load and loading sequence on LV TDE velocities. METHODS: Forty-eight subjects underwent echo Doppler and color-coded TDE with comprehensive noninvasive vascular assessment. Arterial afterload was measured by effective arterial elastance (Ea) and systemic vascular resistance index (SVRI), and loading sequence was quantified by early- (carotid characteristic impedance [Zc]) and late-systolic loads (augmentation index [cAI]; late pressure-time integral [PTI3]). Vascular stiffness was measured by carotid-femoral pulse wave velocity (PWV) and total arterial compliance. RESULTS: Early-diastolic velocity (E') varied inversely with Zc, SVRI, Ea, and PWV (r = -0.4 to 0.5; beta = 1.0 to 1.2; p < or = 0.004), but late-systolic load (cAI and PTI3 r = -0.6; beta = 1.6; both p < 0.0001) and arterial compliance (r = 0.6; beta = 1.4; p < 0.0001) had the strongest associations with E'. Load dependence was not altered by the presence of hypertension, and in multivariate analysis only cAI and Zc significantly predicted E', even after adjusting for age (p < 0.05). Peak systolic velocity was additionally found to be inversely related to afterload, whereas other measures of contractility were not. CONCLUSIONS: Diastolic and systolic tissue velocities vary inversely with arterial afterload, with late-systolic load having the greatest influence on E'. These findings may partly explain the decrease in early relaxation velocity noted with aging, hypertension, and patients with heart failure. Strategies to reduce afterload, vascular stiffening, and wave reflections may prove useful to enhance early diastolic relaxation.
Barry A Borlaug; Vojtech Melenovsky; Margaret M Redfield; Kristy Kessler; Hyuk-Jae Chang; Theodore P Abraham; David A Kass
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2007-10-01
Journal Detail:
Title:  Journal of the American College of Cardiology     Volume:  50     ISSN:  1558-3597     ISO Abbreviation:  J. Am. Coll. Cardiol.     Publication Date:  2007 Oct 
Date Detail:
Created Date:  2007-10-15     Completed Date:  2007-11-20     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8301365     Medline TA:  J Am Coll Cardiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1570-7     Citation Subset:  AIM; IM    
Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.
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MeSH Terms
Aged, 80 and over
Atrial Function / physiology
Blood Flow Velocity / physiology*
Coronary Circulation / physiology*
Diastole / physiology*
Echocardiography, Doppler
Heart Ventricles / ultrasonography
Hypertension / physiopathology
Middle Aged
Multivariate Analysis
Myocardial Contraction / physiology
Stroke Volume / physiology
Systole / physiology*
Vascular Resistance / physiology
Ventricular Function, Left / physiology*
Grant Support

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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