Document Detail

Discrepancy between cardiac and physical functional reserves in stroke.
MedLine Citation:
PMID:  22363066     Owner:  NLM     Status:  MEDLINE    
BACKGROUND AND PURPOSE: Understanding the physiological limitations to exercise after stroke will assist the development of targeted therapies to improve everyday function. This study defines (1) whether exercise capacity is limited by the cardiovascular system (oxygen supply) or skeletal muscles (oxygen utilization); and (2) cardiac function and pumping capability in people with stroke.
METHODS: Twenty-eight male participants with mild ischemic stroke (70 ± 6 years of age, 18 ± 20 months poststroke) and 25 male, age-matched healthy control subjects performed a graded cardiopulmonary exercise test with gas exchange and noninvasive hemodynamic measurements. Maximal oxygen extraction was calculated as the ratio between peak oxygen consumption and peak cardiac output. Cardiac function and pumping capability were assessed by peak exercise cardiac power output (expressed in watts) and cardiac output.
RESULTS: Peak oxygen consumption (18.4 ± 4.6 versus 26.8 ± 5.5 mL/kg/min, P<0.01) and arterial-venous O(2) difference (9.3 ± 2.5 versus 12.6 ± 1.9 mlO(2)/100 mL of blood, P<0.01) were both reduced in stroke participants compared with healthy control subjects. In contrast, peak exercise cardiac power output (4.79 ± 0.79 versus 4.51 ± 0.96 W, P=0.49), cardiac output (16.4 ± 3.1 versus 17.1±2.5 L/min, P=0.41), and the pressure-generating capacity of the heart (127±11 versus 125 ± 14 mm Hg, P=0.97) were similar between stroke participants and healthy control subjects.
CONCLUSIONS: The ability of skeletal muscles to extract oxygen is diminished after stroke. However, cardiac function and pumping capability are maintained. Appropriate therapies targeting muscle oxygen uptake such as exercise rehabilitation may improve exercise capacity after stroke.
Djordje G Jakovljevic; Sarah A Moore; Lip-Bun Tan; Lynn Rochester; Gary A Ford; Michael I Trenell
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2012-02-23
Journal Detail:
Title:  Stroke; a journal of cerebral circulation     Volume:  43     ISSN:  1524-4628     ISO Abbreviation:  Stroke     Publication Date:  2012 May 
Date Detail:
Created Date:  2012-04-24     Completed Date:  2012-08-16     Revised Date:  2014-03-14    
Medline Journal Info:
Nlm Unique ID:  0235266     Medline TA:  Stroke     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1422-5     Citation Subset:  IM    
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MeSH Terms
Cardiac Output / physiology
Case-Control Studies
Exercise / physiology*
Exercise Therapy
Heart / physiology*
Middle Aged
Muscle, Skeletal / metabolism
Oxygen / metabolism
Oxygen Consumption / physiology
Stroke / metabolism*,  physiopathology*,  rehabilitation
Grant Support
G0700718//Medical Research Council; G0900686//Medical Research Council; MC_G0802536//Medical Research Council; SRF-2011-04-017//Department of Health
Reg. No./Substance:
Comment In:
Stroke. 2012 Sep;43(9):e91; author reply e92   [PMID:  22744647 ]

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

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