title: Coronary Flow Reserve of the Non-Ischemia Related Coronary Artery During Dobutamine Stress Echocardiography.
abstract: BACKGROUND
  Incorporation of analysis of coronary velocities in stress studies adds diagnostic value to both clinical variables and dobutamine echocardiography. Micorcirculatory abnormalities may precede obstructive corornary disease. Therefore the aim of this study was to assess Doppler derived coronary velocity and flow of the left anterior descending coronary artery (LAD) during dobutamine stress echocardiography (DSE) in patients without LAD-related ischemia.
  
  
  METHODS
  Sixty nine patients with chest pain underwent DSE studies to evaluate myocardial ischemia. All had trans-thoracic Doppler interrogation of the distal LAD before and just after termination of the DSE. Coronary velocity reserves (CFR) were calculated as the ratios of post-DSE/baseline diastolic velocities. Volumetric flow in the distal LAD was calculated from the diameter of LAD color jet and velocity integral. Volumetric flow reserve was calculated as the ratio of post-DSE baseline LAD flows.
  
  
  RESULTS
  At rest all subjects had left ventricular wall motion score index (WMSI) = 1, while in 28, wall motion abnormality appeared in non-LAD territory with WMSI = 1.17 ± 0.08. Peak diastolic velocity after DSE increased form 28.5 ± 13.6 to 52.4 ± 23.7 cm/sec, P = 9.5 × 10-11, and velocity-CFR was 2.08 ± 0.7. Diastolic LAD flow increased from 36.5 ± 23.8 to 75.75 ± 48.7 mL/min, P = 1.21 × 10-7and volumetric-CFR was 2.6 ± 2.8. Peak diastolic velocity-CFR in patients without LV wall motion abnormality was 2.4 ± 0.7 while in those with motion abnormality 1.77 ± 0.56, P = 0.00008. Flow-derived LAD-CFR was 3.3 ± 3.7 in those without compared to 1.88 ± 0.57 in patients with wall motion abnormality, P < 0.05.
  
  
  CONCLUSIONS
  LAD velocity and flow reserves are reduced in patients with remote myocardial ischemia, which may indicate early atherosclerotic involvement.
authors.affiliation: Department of Cardiology, Bnai Zion Medical Center, Haifa, Israel; Technion - Israel Institute of Technology, Haifa, Israel.
authors.forename: Dawod
authors.initials: D
authors.lastname: Sharif
authors.affiliation: Technion - Israel Institute of Technology, Haifa, Israel.
authors.forename: Amal
authors.initials: A
authors.lastname: Sharif-Rasslan
authors.affiliation: Department of Cardiology, Bnai Zion Medical Center, Haifa, Israel.
authors.forename: Camilia
authors.initials: C
authors.lastname: Shahla
authors.affiliation: Department of Cardiology, Bnai Zion Medical Center, Haifa, Israel.
authors.forename: Amin
authors.initials: A
authors.lastname: Khalil
authors.affiliation: Department of Cardiology, Bnai Zion Medical Center, Haifa, Israel; Technion - Israel Institute of Technology, Haifa, Israel.
authors.forename: Uri
authors.initials: U
authors.lastname: Rosenschein
keywords: Coronary flow reserve; Dobutamine stress echocardiography; Myocardial ischemia