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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2001-4-10
pubmed:abstractText
Various combinations of sympathetic and vagal tone can yield the same heart rate, while ventricular electrophysiology differs. To demonstrate this in humans, we studied healthy volunteers in the sitting position with horizontal legs. First, heart rate was increased by lowering the legs to 60 degrees and back. Thereafter, heart rate was increased by handgrip. In each subject, a leg-lowering angle was selected at which heart rate matched best with heart rate in the third handgrip minute. Thirteen subjects had a heart rate match better than 1%. Heart rate (control: 65.2+/-9.0 bpm) increased to 72.1+/-8.7 (leg lowering) and to 72.1+/-8.8 (handgrip) bpm. QRS azimuth, QRS duration, maximal T vector, T azimuth, T elevation, ST duration, QRS-T angle and QT interval differed significantly (P<0.05) between leg lowering and handgrip (QT interval 418+/-15 versus 435+/-21 ms). Also, septal dispersion of repolarization, assessed as the time difference between the apex and the end of the T wave in the V2 and V3 leads, differed significantly (V2: 96.7+/-19.3 versus 110.0+/-23.3 ms, P<0.01; V3: 88.7+/-19.3 versus 97.3+/-23.3 ms; P<0.01). Hence, leg lowering and handgrip cause different ventricular depolarization and repolarization. The hypertensive handgrip manoeuvre entails a longer QT interval and probably an increased septal dispersion of repolarization.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0031-6768
pubmed:author
pubmed:issnType
Print
pubmed:volume
441
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
717-24
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Within-subject electrocardiographic differences at equal heart rates: role of the autonomic nervous system.
pubmed:affiliation
Cardiology Department, Leiden University Medical Center, The Netherlands.
pubmed:publicationType
Journal Article