title: Differential characterization of blood flow, velocity, and vascular resistance between proximal and distal normal epicardial human coronary arteries: analysis by intracoronary Doppler spectral flow velocity.
abstract: To characterize coronary blood flow velocity parameters and to determine the relation among velocity, volumetric flow, and vascular resistance in awake human beings, we performed paired proximal and distal velocity measurements in 28 angiographically normal coronary arteries. Mean velocity, peak velocity, diastolic-to-systolic velocity ratio, and diameter and cross-sectional area of proximal and distal arteries were determined and coronary flow and vascular resistance computed. Mean velocity and coronary vasodilator reserve were similar for all three native arteries and were preserved from proximal to distal segments. Volumetric flow decreased from proximal to distal segments. The demonstrated inverse and curvilinear (polynomial) relation between volumetric flow and vascular resistance agrees with theoretical and animal models of coronary physiologic characteristics and suggests a nadir of coronary vascular resistance below which coronary flow no longer increases.
authors.affiliation: Department of Internal Medicine, St. Louis University Health Sciences Center, Mo., USA.
authors.forename: E O
authors.initials: EO
authors.lastname: Ofili
authors.forename: M J
authors.initials: MJ
authors.lastname: Kern
authors.forename: J A
authors.initials: JA
authors.lastname: St Vrain
authors.forename: T J
authors.initials: TJ
authors.lastname: Donohue
authors.forename: R
authors.initials: R
authors.lastname: Bach
authors.forename: B
authors.initials: B
authors.lastname: al-Joundi
authors.forename: F V
authors.initials: FV
authors.lastname: Aguirre
authors.forename: R
authors.initials: R
authors.lastname: Castello
authors.forename: A J
authors.initials: AJ
authors.lastname: Labovitz
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001783:Blood Flow Velocity; D017023:Coronary Angiography; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000502:physiology; D005260:Female; D006801:Humans; D006940:Hyperemia / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012016:Reference Values; D018608:Ultrasonography, Doppler / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D014655:Vascular Resistance