Linked Life Data

6682722

Source:http://linkedlifedata.com/resource/pubmed/id/6682722

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1983-7-15
pubmed:abstractText
Triggered activity developed in depolarized Purkinje fibers (maximum diastolic potential -59.3 +/- 9.9 mV) during superfusion with normal Tyrode's solution in 84% of subendocardial preparations from 1-day-old canine infarct. Triggered activity occurred when a delayed afterdepolarization attained threshold potential and spontaneously terminated after a subthreshold delayed afterdepolarization. Triggered activity was initiated either by stimulated beats or by the background slow Purkinje automaticity. When multiple stimulated beats were required, the amplitude of the afterdepolarization increased and the coupling interval decreased when the stimulation frequency and/or the number of stimulated beats increased. Varying degrees of entrance and exit block around sites of triggered activity were common, and some triggered activity manifested as a parasystolic rhythm. In preparations showing subthreshold delayed afterdepolarizations, both epinephrine (2.5 x 10(-6) M) and increasing [Ca++]o, (from 2.7 to 8.1 mM) increased the amplitude of afterdepolarizations and resulted in triggered activity. On the other hand, verapamil (2.2 x 10(-6) M) resulted in exit block around sites of triggered activity and/or completely suppressed afterdepolarizations and triggered activity. Isochronal mapping of endocardial activation during the initiation and perpetuation of triggered activity elucidated a focal site of origin from Purkinje fibers overlying the infarct and showed no evidence of a circus movement of excitation. The in vitro triggered activity may explain the spontaneous multiform ventricular rhythms seen in the intact heart.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0009-7330
pubmed:author
pubmed:issnType
Print
pubmed:volume
52
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
566-79
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Triggered ventricular rhythms in 1-day-old myocardial infarction in the dog.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, Non-P.H.S.