Document Detail


Effect of acute calcium slow-channel antagonism on the cardiorespiratory response to graded exercise testing.
MedLine Citation:
PMID:  3793333     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The effect of acute calcium slow-channel antagonism on the cardiorespiratory responses of 12 healthy males was studied during multistage maximal exercise testing. Oral diltiazem (60 mg), nifedipine (10 mg), verapamil (80 mg), and placebo were administered in a randomized double-blind crossover fashion 1.5 h before an intermittent multistage cycle ergometer exercise test. At peak effort, heart rate, pulmonary ventilation, CO2 production, and respiratory exchange ratio were not significantly modified by drug ingestion. In contrast, maximal O2 consumption (2.6% reduction, P less than 0.02) and performance time (6.4% reduction, P less than 0.02) were reduced by nifedipine. During submaximal exercise, the chronotropic response was accentuated by nifedipine but not by diltiazem or verapamil. Furthermore, nifedipine altered the relationship of percentage of maximal O2 consumption to percentage of maximal heart rate, and both the relative and absolute O2 consumption corresponding to 70% and 85% of the maximal heart rate were significantly reduced after nifedipine ingestion. The results indicated that in persons without symptomatic coronary artery disease exercise performed at a given percentage of the maximal heart rate will yield a lower than expected relative and absolute intensity in the presence of acute nifedipine-induced calcium slow-channel antagonism.
Authors:
N F Gordon; J P van Rensburg; D L Kawalsky; H M Russell; C P Celliers; D P Myburgh
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Publication Detail:
Type:  Clinical Trial; Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  International journal of sports medicine     Volume:  7     ISSN:  0172-4622     ISO Abbreviation:  Int J Sports Med     Publication Date:  1986 Oct 
Date Detail:
Created Date:  1987-02-03     Completed Date:  1987-02-03     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8008349     Medline TA:  Int J Sports Med     Country:  GERMANY, WEST    
Other Details:
Languages:  eng     Pagination:  254-8     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Adult
Calcium Channel Blockers / pharmacology*
Diltiazem / pharmacology
Exercise Test
Heart Rate / drug effects*
Humans
Male
Nifedipine / pharmacology
Oxygen Consumption / drug effects*
Pulmonary Gas Exchange / drug effects*
Respiratory Function Tests
Verapamil / pharmacology
Chemical
Reg. No./Substance:
0/Calcium Channel Blockers; 21829-25-4/Nifedipine; 42399-41-7/Diltiazem; 52-53-9/Verapamil

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


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