Linked Life Data

3731429

Source:http://linkedlifedata.com/resource/pubmed/id/3731429

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1986-9-17
pubmed:abstractText
We studied the effects of ischemia on transmembrane action potentials, conduction time, and refractory periods of both endocardial and epicardial muscle cells of coronary-perfused cat left ventricles. Oxygenated Tyrode's solution was perfused through the left anterior descending coronary artery, while the preparation was superfused with Tyrode's solution gassed with 95% N2 and 5% CO2. Transmembrane action potentials recorded simultaneously from endocardial and epicardial cells were normal during coronary perfusion. When perfusion was discontinued ("ischemia"), rapid deterioration of action potentials and prolongation of conduction time were observed in both endocardial and epicardial cells. The magnitude of the reduction of action potential amplitude and action potential duration (APD), and of prolongation of conduction time, was greater in epicardial cells than in endocardial cells, although the change in resting membrane potential was almost the same. However, APD of endocardial cells decreased progressively during 30 min of ischemia, whereas APD of epicardial cells was reduced maximally at 10 min and then partially recovered. Shortening of refractory periods of endocardial cells paralleled APD shortening, whereas refractory periods of epicardial cells decreased for the first 10 min and then increased. At 10 min of ischemia, APD and refractory periods of epicardial cells were significantly shorter than those of endocardial cells. At 30 min of ischemia, refractory periods of epicardial cells exceeded those of endocardial cells because of development of greater postrepolarization refractoriness in epicardial cells. Accompanying these different changes in APD and refractory periods of endocardial and epicardial cells, spontaneous extrasystolic impulses increased and rapid runs of extrasystolic impulses could be induced by extrastimuli.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0009-7322
pubmed:author
pubmed:issnType
Print
pubmed:volume
74
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
401-9
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Simultaneous recording of action potentials from endocardium and epicardium during ischemia in the isolated cat ventricle: relation of temporal electrophysiologic heterogeneities to arrhythmias.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't