Linked Life Data

9534283

Source:http://linkedlifedata.com/resource/pubmed/id/9534283

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1998-5-5
pubmed:abstractText
The autonomic tone has been shown to influence the duration of the QT interval, however the independent contribution of sympathetic and parasympathetic tone is not fully elucidated. The influence of autonomic tone on QT duration was studied in 10 young healthy volunteers by evaluating the changes in QT and RR duration induced by i.v. isoproterenol infusion and by standing before and after i.v. administration of propranolol or atropine. Furthermore, the relationship between RR interval and QT duration was evaluated during nocturnal sinus arrhythmia and submaximal exercise test. Low doses of isoproterenol reduced RR (p < 0.01) but not QT interval duration, while higher doses influenced both RR (p < 0.0001) and QT (p < 0.001) duration. Propranolol did not influence standing-induced shortening of RR and QT intervals; on the contrary, atropine administration abolished standing-induced QT interval shortening, without influencing RR changes. QT duration resulted significantly related to preceding RR interval at peak exercise (r = 0.87, p < 0.001) and during nocturnal sinus arrhythmia (r = 0.73, p < 0.0005), however, the regression lines showing the correlation between QT and preceding RR interval were different. Both sympathetic and parasympathetic tone appear to contribute to heart rate-independent changes in QT duration. In the basal state parasympathetic more than sympathetic tone influences the relation QT-heart rate. Major increases of sympathetic nervous system activity may change the relation QT-heart rate. Thus, in case of abrupt autonomic changes, any proposed formula for heart rate correction of QT may result inappropriate, also in the normal range of heart rate.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0393-1978
pubmed:author
pubmed:issnType
Print
pubmed:volume
42
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1071-6
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Influence of autonomic tone on QT interval duration.
pubmed:affiliation
Divisione di Cardiologia, Ospedale Cardarelli, Napoli.
pubmed:publicationType
Journal Article, Clinical Trial, Controlled Clinical Trial