Linked Life Data

9127390

Source:http://linkedlifedata.com/resource/pubmed/id/9127390

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4 Pt 1
pubmed:dateCreated
1997-7-10
pubmed:abstractText
A three phase relation has been demonstrated between increasing heart rate and cardiac output at rest. Phase I with cardiac output increasing with increasing heart rate, phase II a plateau, and phase III decreasing cardiac output with any further increase in heart rate. The "optimal rate" can be defined as the heart rate at the onset of phase II. Twenty patients were studied, 13 male, mean age 60 years (range 31-71 years). All had chronic complete heart block and established DDD pacing. A maximal exercise test was performed to determine peak sinus rate. Exercise hemodynamics were measured using an ambulatory monitor (Capintec Vest), which permits measurement of relative cardiac output and relative ejection fraction. The patients were programmed to VVI pacing at a rate of 60 beats/min and performed three exercise tests at different workloads. The order of workloads was randomized and selected from a range (0, 25, 50, or 75 W) depending on fitness. After 3-minute stabilization, the VVI pacing rate was increased at 1-minute intervals until higher than peak sinus rate giving a total exercise time of 12 minutes. The "optimal rate band" was determined at each workload. The mean of this "optimal rate band" for each workload varied in a nonlinear manner. There was no correlation between "mean optimal rate" and age or the peak rate predicted by the Astrand formula. Current definitions of chronotropic incompetence are inaccurate. Are some of these people at their "optimal rate" already? The arbitrary selection of rate response curves on age related criteria may lead to an impaired hemodynamic response.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0147-8389
pubmed:author
pubmed:issnType
Print
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
866-73
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
The optimal pacing rate: an unpredictable parameter.
pubmed:affiliation
Research Registrar, Glenfield Hospital, Leicestershire, United Kingdom.
pubmed:publicationType
Journal Article, Clinical Trial, Randomized Controlled Trial