Linked Life Data

7446173

Source:http://linkedlifedata.com/resource/pubmed/id/7446173

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1981-2-26
pubmed:abstractText
Autonomic nervous alterations have generally been held responsible for the bradycardia of the endurance athlete. In order to determine whether there is also a non-autonomic component in the bradycardia of long-term training, we compared the intrinsic heart rate (HR) of highly trained bicyclists (heart volume: 995 +/- 155 ml) with that of untrained men (heart volume: 805 +/- 195 ml) at rest and during bicycle ergometer exercise at 50, 75 and 100% of maximal oxygen uptake (VO2 max.) Intrinsic HR was achieved by combined vagal and beta-adrenergic blockade with atropine and propranolol or metoprolol (cardioselective) injected intravenously. Intrinsic HR was significantly lower in trained (T) than in untrained (UT) at rest and at all levels of exercise. The chronotropic reserve from resting HR to maximal HR was identical in the two groups. Nearly identical intrinsic HRs were achieved with atropine and either beta-adrenergic antagonist. HR differences between T and UT were very similar in magnitude--approximately 13 beats/min--at rest and during exercise at a given percentage of VO2 max, with and without autonomic blockade. Evidence is thus provided for a non-autonomic component in the bradycardia of well-trained men which may be responsible for a parallel downward shift in the relationship between HR and percentage of VO2 max. The lower intrinsic HR in well-trained men might be explained by, i.a. the cardiac enlargement.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0001-6772
pubmed:author
pubmed:issnType
Print
pubmed:volume
109
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
297-305
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1980
pubmed:articleTitle
Non-autonomic component in bradycardia of endurance trained men at rest and during exercise.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't