title: Electrographic Response of the Heart to Myocardial Ischemia.
abstract: Electrocardiographic (ECG) ST segment shifts are often used as markers for detecting myocardial ischemia. Literature suggests that the progression of ischemia, occurs from the endocardium and spreads towards the epicardium, eventually becoming transmural. Our study with animal models has found the progression of ischemia, characterized by ST elevations to be more complex and heterogeneous in its distribution. We used in situ canine preparations, wherein the animals were subjected to demand ischemia by reducing coronary flow and raising the heart rate through atrial pacing. At reduced flow, increasing the heart rate caused pockets of ST elevations to appear variously distributed in the sub-epicardial, midmyocardial and endocardial regions. Further reduction in coronary flow with simultaneous raising of the heart rate, increased the extent and magnitude of ST elevated regions, that in certain cases became transmural.
authors.affiliation: Bioengineering Department, University of Utah, Salt Lake City, UT, USA; CVRTI, University of Utah, Salt Lake City, UT, USA; SCI Institute, University of Utah, Salt Lake City, UT, USA.
authors.forename: K K
authors.initials: KK
authors.lastname: Aras
authors.affiliation: Boston Scientific, Minneapolis, MN, USA.
authors.forename: S
authors.initials: S
authors.lastname: Shome
authors.affiliation: Bioengineering Department, University of Utah, Salt Lake City, UT, USA; CVRTI, University of Utah, Salt Lake City, UT, USA; SCI Institute, University of Utah, Salt Lake City, UT, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Swenson
authors.affiliation: CVRTI, University of Utah, Salt Lake City, UT, USA; SCI Institute, University of Utah, Salt Lake City, UT, USA.
authors.forename: J
authors.initials: J
authors.lastname: Stinstra
authors.affiliation: Bioengineering Department, University of Utah, Salt Lake City, UT, USA; CVRTI, University of Utah, Salt Lake City, UT, USA; SCI Institute, University of Utah, Salt Lake City, UT, USA.
authors.forename: R S
authors.initials: RS
authors.lastname: MacLeod