Linked Life Data

18347833

Source:http://linkedlifedata.com/resource/pubmed/id/18347833

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2008-6-26
pubmed:abstractText
The reduced power of the failing heart can be ascribed to a combination of reduced force and slower contraction. We hypothesized that these two properties are due to different cellular mechanisms. We measured contraction parameters both in vivo and in isolated left ventricular (LV) cardiomyocytes from a rat model of post infarction congestive heart failure (CHF). ECG was measured simultaneously with echocardiography and LV pressure, respectively. Shortening and shortening velocity (SV) in isolated cardiomyocytes were measured during different stimulation protocols. LV end diastolic pressure (LVEDP) was 24.6 +/- 0.7 mmHg in CHF. LV systolic pressure was decreased by 20%, maximum rate of pressure development in the LV (+dP/dtmax) by 36% and time in systole increased by 20% in CHF compared to sham. Electrical remodelling occurred in CHF cells, which were depolarized and had prolonged action potentials (AP) compared to sham cells. Fractional shortening (FS) was increased in CHF compared to sham independent of stimulation protocol. Larger FS was accompanied by increased sarcoplasmic reticulum (SR) Ca2+ load and depended on the electrical remodelling. Time to peak contraction (TTP) was increased in CHF compared to sham cells, but in contrast to FS, TTP was only slightly affected when the cells were stimulated with sham APs and sham diastolic membrane potential (DMP). Contraction duration (corresponding to systolic duration) was 25% longer in CHF than in sham independent on stimulation protocol. We conclude that electrical remodelling affecting DMP and AP duration (APD) significantly affects the size of contraction, whereas the mechanism for slowing of contraction in CHF is different.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0300-8428
pubmed:author
pubmed:issnType
Print
pubmed:volume
103
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
328-44
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Slow contractions characterize failing rat hearts.
pubmed:affiliation
Institute for Experimental Medical Research, Ullevaal University Hospital, 0407, Oslo, Norway. janny.bokenes@medisin.uio.no
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't