Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2010-8-31
pubmed:abstractText
We have generated transgenic rabbits lacking cardiac slow delayed-rectifier K(+) current [I(Ks); long QT syndrome type 1 (LQT1)] or rapidly activating delayed-rectifier K(+) current [I(Kr); long QT syndrome type 2 (LQT2)]. Rabbits with either genotype have prolonged action potential duration and QT intervals; however, only LQT2 rabbits develop atrioventricular (AV) blocks and polymorphic ventricular tachycardia. We therefore sought to characterize the genotype-specific differences in AV conduction and ventricular refractoriness in LQT1 and LQT2 rabbits. We carried out in vivo electrophysiological studies in LQT1, LQT2, and littermate control (LMC) rabbits at baseline, during isoproterenol infusion, and after a bolus of dofetilide and ex vivo optical mapping studies of the AV node/His-region at baseline and during dofetilide perfusion. Under isoflurane anesthesia, LQT2 rabbits developed infra-His blocks, decremental His conduction, and prolongation of the Wenckebach cycle length. In LQT1 rabbits, dofetilide altered the His morphology and slowed His conduction, resulting in intra-His block, and additionally prolonged the ventricular refractoriness, leading to pseudo-AV block. The ventricular effective refractory period (VERP) in right ventricular apex and base was significantly longer in LQT2 than LQT1 (P < 0.05) or LMC (P < 0.01), with a greater VERP dispersion in LQT2 than LQT1 rabbits. Isoproterenol reduced the VERP dispersion in LQT2 rabbits by shortening the VERP in the base more than in the apex but had no effect on VERP in LQT1. EPS and optical mapping experiments demonstrated genotype-specific differences in AV conduction and ventricular refractoriness. The occurrence of infra-His blocks in LQT2 rabbits under isoflurane and intra-His block in LQT1 rabbits after dofetilide suggest differential regional sensitivities of the rabbit His-Purkinje system to drugs blocking I(Kr) and I(Ks).
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-10533588, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-11227963, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-11514288, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-12354568, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-12411393, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-1279316, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-14769705, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-14998624, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-15978848, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-17027019, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-17467631, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-17496219, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-17533421, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-17675081, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-18184962, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-18347223, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-18373596, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-18464931, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-18682043, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-18757866, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-18835916, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-1918714, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-19675070, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-2856866, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-3943175, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-3993530, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-7628036, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-7889573, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-8099317, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-8389123, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-9386136, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-9501192, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-9518735, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-9835268, http://linkedlifedata.com/resource/pubmed/commentcorrection/20581090-9930915
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1522-1539
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
299
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H643-55
pubmed:dateRevised
2011-9-13
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Electrophysiological studies of transgenic long QT type 1 and type 2 rabbits reveal genotype-specific differences in ventricular refractoriness and His conduction.
pubmed:affiliation
Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural