Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1996-4-9
pubmed:abstractText
Cardiac output (CO) responses to exercise can be altered by ventricular pacing in pacemaker-dependent patients. The relative contributions of CO and peripheral vascular resistance (PVR) toward the initial increase in blood pressure with the initiation of static exercise were investigated in eight otherwise healthy pacemaker-dependent subjects [age 24 +/- 2 yr (range 17-37 yr)]. Beat-by-beat measures of heart rate (HR; electrocardiography), mean arterial pressure (MAP), and CO derived from stroke volume (SV) (CO = HR.SV; 2-D echocardiography) were determined during the first 20 s of a one-legged static knee extension performed at 20% maximal voluntary effort by using three pacing modalities: dual pacing and sensing mode (DDD, i.e., normal physiological HR response), fixed at resting HR (DOO-R), and fixed at peak exercise HR (DOO-E), as previously achieved during 5 min of sustained contraction in the DDD mode. There were no differences in MAP, CO, or PVR (PVR = MAP/CO) between modes at rest (P > 0.05). With DOO-E pacing, SV was lower at rest compared with the other modes and increased with exercise (P < 0.05). Although there were no significant increase in MAP or CO during DOO-R pacing, both variables were elevated by leg contraction during DDD and DOO-E pacing (P < 0.05), with no significant change in PVR. Additionally, the CO and MAP increases were significantly greater with DOO-E pacing (P < 0.05). Thus the magnitude of the initial increase in arterial pressure at the onset of mild one-legged static exercise was dictated by the changes in CO as PVR remained unchanged.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
79
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1668-72
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Cardiovascular responses at the onset of static exercise in patients with dual-chamber pacemakers.
pubmed:affiliation
Harry S. Moss Heart Center, University of Texas Southwestern Medical Center, Dallas 75235-9034, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't