title: Model prediction of subendocardial perfusion of the coronary circulation in the presence of an epicardial coronary artery stenosis.
abstract: The subendocardium is most vulnerable to ischemia, which is ameliorated by relaxation during diastole and increased coronary pressure. Recent clinical techniques permit the measuring of subendocardial perfusion and it is therefore important to gain insight into how measurements depend on perfusion conditions of the heart. Using data from microsphere experiments a layered model of the myocardial wall was developed. Myocardial perfusion distribution during hyperemia was predicted for different degrees of coronary stenosis and at different levels of Diastolic Time Fraction (DTF). At the reference DTF, perfusion was rather evenly distributed over the layers and the effect of the stenosis was homogenous. However, at shorter or longer DTF, the subendocardium was the first or last to suffer from shortage of perfusion. It is therefore concluded that the possible occurrence of subendocardial ischemia at exercise is underestimated when heart rate is increased and DTF is lower.
authors.affiliation: Department of Medical Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. J.P.vandenwijngaard@amc.uva.nl
authors.forename: Jeroen P H M
authors.initials: JP
authors.lastname: van den Wijngaard
authors.forename: Christina
authors.initials: C
authors.lastname: Kolyva
authors.forename: Maria
authors.initials: M
authors.lastname: Siebes
authors.forename: Jenny
authors.initials: J
authors.lastname: Dankelman
authors.forename: Martin J C
authors.initials: MJ
authors.lastname: van Gemert
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Piek
authors.forename: Jos A E
authors.initials: JA
authors.lastname: Spaan
mesh_terms: D003326:Coronary Circulation / Q000502:physiology*; D023921:Coronary Stenosis / Q000503:physiopathology*; D003971:Diastole; D004699:Endocardium / Q000503:physiopathology*; D006801:Humans; D008955:Models, Cardiovascular; D012039:Regional Blood Flow