Document Detail


Cardiac function following prolonged exercise: influence of age.
MedLine Citation:
PMID:  21436460     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
This study sought to determine the influence of age on the left ventricular (LV) response to prolonged exercise (150 min). LV systolic and diastolic performance was assessed using echocardiography (ECHO) before (pre) and 60min following (post) exercise performed at 80% VO(2)max in young (28±4.5 years; n=18; mean±SD) and middle-aged (52±3.9 years; n=18) participants. LV performance was assessed using 2D echo, including speckle-tracking imaging, to determine LV strain (LV S) and strain rate (LV SR), in addition to Doppler measures of diastolic function. We observed a post-exercise elevation in LV S (young: -19.5±2.1% vs. -21.6±2.1%, middle-aged: -19.9±2.3% vs. -20.8±2.1%, p<0.05) and LV SR (young: -1.19±0.1 vs. -1.37±0.2; middle-aged: -1.20±0.2 vs. -1.38±0.2, p<0.05) during recovery in both groups. Diastolic function was reduced during recovery, including the LV strain rate (SRe/a), in young (2.35±0.7 vs. 1.89±0.5, p<0.01) and middle-aged (1.51±0.5 vs. 1.05±0.2, p<0.01) participants, as were conventional indices including the E/A ratio. Dobutamine stress ECHO revealed a post-exercise depression in LV S in response to increasing dobutamine dose, which was similar in both young (pre-exercise dobutamine 0 vs. 20 μg kg(-1) min(-1): -19.5±2.1 vs. -27.2±2.2%, post-exercise dobutamine 0 vs. 20 μg kg(-1) min(-1): -21.6±2.1 vs. -23.7±2.2%, p<0.05) and middle-aged participants (pre: -19.9±2.3 vs. -25.3±2.7%, post: -20.8±2.1 vs. -23.5±2.7, p<0.05). This is despite higher nor-adrenaline concentrations immediately post-exercise in the middle-aged participants compared to young (4.26±2.7 nmol/L vs. 3.00±1.4 nmol/L; p=0.12). These data indicate that LV dysfunction is observed following prolonged exercise and that advancing age does not increase the magnitude of this response.
Authors:
Laura Banks; Zion Sasson; Sam Esfandiari; Gian-Marco Busato; Jack M Goodman
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2011-3-24
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  -     ISSN:  1522-1601     ISO Abbreviation:  -     Publication Date:  2011 Mar 
Date Detail:
Created Date:  2011-3-25     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Affiliation:
1University of Toronto.
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