title: Assessing coronary blood flow dynamics with the TIMI frame count method: comparison with simultaneous intracoronary Doppler and ultrasound.
abstract: This study compared the TIMI frame count (TFC), which has been proposed as a method for quantifying coronary blood flow, with coronary flow and microvascular function measured with intracoronary Doppler and intracoronary ultrasound. Coronary blood flow volume was calculated from coronary blood velocity (by intracoronary Doppler) and lumen area (by intracoronary ultrasound) in the LAD in 46 post-heart transplant patients at baseline and after intracoronary adenosine. TFC correlated significantly with average peak coronary blood velocity (r = -0.42; P = 0.004) and coronary lumen area (r = 0.39; P = 0.008), but not with coronary blood flow volume (r = -0.01; P = 0.96) or the coronary flow reserve response to adenosine (r = 0.09; P = 0.58). In conclusion, TFC is a simple method of assessing coronary blood velocity but not volumetric flow. While TFC does not predict coronary flow reserve, as a measure of velocity it does provide an assessment of basal microvascular tone, information that is complementary to that afforded by flow reserve measurements.
authors.affiliation: Division of Cardiology, Cook County Hospital, Chicago, Illinois, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Tanedo
authors.forename: R F
authors.initials: RF
authors.lastname: Kelly
authors.forename: M
authors.initials: M
authors.lastname: Marquez
authors.forename: D E
authors.initials: DE
authors.lastname: Burns
authors.forename: L W
authors.initials: LW
authors.lastname: Klein
authors.forename: M R
authors.initials: MR
authors.lastname: Costanzo
authors.forename: J E
authors.initials: JE
authors.lastname: Parrillo
authors.forename: S M
authors.initials: SM
authors.lastname: Hollenberg
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D015331:Cohort Studies; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000000981:diagnostic imaging; D005260:Female; D006339:Heart Rate / Q000502:physiology; D016027:Heart Transplantation / Q000000981:diagnostic imaging; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D008722:Methods; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology; D018608:Ultrasonography, Doppler; D018084:Ultrasonography, Interventional; D014655:Vascular Resistance / Q000502:physiology