title: Absolute coronary blood flow measurement and microvascular resistance in ST-elevation myocardial infarction in the acute and subacute phase.
abstract: OBJECTIVE
  In a number of patients with acute myocardial infarction (AMI), myocardial hypoperfusion, known as the no-reflow phenomenon, persists after primary percutaneous intervention (PPCI). The aim of this study was to evaluate the feasibility and safety of a new quantitative method of measuring absolute blood flow and resistance within the perfusion bed of an infarct-related artery. Furthermore, we sought to study no-reflow by correlating these measurements to the index of microvascular resistance (IMR) and the area at risk (AR) as determined by cardiac magnetic resonance imaging (CMR).
  
  
  METHODS
  Measurements of absolute flow and myocardial resistance were performed in 20 patients with ST-segment elevation myocardial infarction (STEMI), first immediately following PPCI and then again after 3-5days. These measurements used the technique of thermodilution during a continuous infusion of saline. Flow was expressed in ml/min per gram of tissue within the area at risk.
  
  
  RESULTS
  The average time needed for measurement of absolute flow, resistance and IMR was 20min, and all measurements could be performed without complication. A higher flow supplying the AR correlated with a lower IMR in the acute phase. Absolute flow increased from 3.14 to 3.68ml/min/g (p=0.25) and absolute resistance decreased from 1317 to 1099 dyne.sec.cm-5/g (p=0.40) between the first day and fifth day after STEMI.
  
  
  CONCLUSIONS
  Measurement of absolute flow and microvascular resistance is safe and feasible in STEMI patients and may allow for a better understanding of microvascular (dys)function in the early phase of AMI.
authors.affiliation: Department of Cardiology, Catharina Hospital, Eindhoven, The Netherlands; Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors.forename: Inge
authors.initials: I
authors.lastname: Wijnbergen
authors.affiliation: Department of Cardiology, Catharina Hospital, Eindhoven, The Netherlands; Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors.forename: Marcel
authors.initials: M
authors.lastname: van 't Veer
authors.affiliation: Department of Cardiology, Catharina Hospital, Eindhoven, The Netherlands.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Lammers
authors.affiliation: Department of Cardiology, Catharina Hospital, Eindhoven, The Netherlands.
authors.forename: Joey
authors.initials: J
authors.lastname: Ubachs
authors.affiliation: Department of Cardiology, Catharina Hospital, Eindhoven, The Netherlands; Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands. Electronic address: nico.pijls@cze.nl.
authors.forename: Nico H J
authors.initials: NH
authors.lastname: Pijls
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000503:physiopathology*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008833:Microcirculation; D055806:Microvessels / Q000503:physiopathology*; D008875:Middle Aged; D054318:No-Reflow Phenomenon / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects*; D011237:Predictive Value of Tests; D012039:Regional Blood Flow; D000072657:ST Elevation Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D013815:Thermodilution / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome; D014655:Vascular Resistance
keywords: Absolute flow; Microvascular dysfunction; STEMI