title: Real-time assessment of myocardial perfusion and wall motion during bicycle and treadmill exercise echocardiography: comparison with single photon emission computed tomography.
abstract: OBJECTIVE
  We sought to determine the feasibility and accuracy of real-time imaging of myocardial contrast echocardiography (MCE) in detecting myocardial perfusion defects during exercise echocardiography compared with radionuclide tomography.
  
  
  BACKGROUND
  Ultrasound imaging at a low mechanical index and frame rate (10 to 20 Hz) after intravenous injections of perfluorocarbon containing microbubbles has the potential to evaluate myocardial perfusion and wall motion (WVM) simultaneously and in real time.
  
  
  METHODS
  One hundred consecutive patients with intermediate-to-high probability of coronary artery disease underwent treadmill (n = 50) or supine bicycle (n = 50) exercise echocardiography. Segmental perfusion with MCE and WM w ere assessed in real time before and at peak exercise using low mechanical index (0.3) and frame rates of 10 to 20 Hz after 0.3 ml bolus injections of intravenous Optison (Mallinckrodt Inc., San Diego, California). All patients had a dual isotope (rest thallium-201, stress sestamibi) study performed during the same exercise session, and 44 patients had subsequent quantitative coronary angiography.
  
  
  RESULTS
  In the 100 patients, agreement between MCE and single photon emission computed tomography (SPECT) was 76%, while it was 88% between MCE and WM assessment. Compared with quantitative angiography, sensitivity of MCE, SPECT and WM was comparable (75%), with a specificity ranging from 81% to 100%. The combination of MCE and WM had the best balance between sensitivity and specificity (86% and 88%,respectively) with the highest accuracy (86%).
  
  
  CONCLUSIONS
  The real-time assessment of myocardial perfusion during exercise stress echocardiography can be achieved with imaging at low mechanical index and frame rates. The combination of WM and MCE correlates well with SPECT and is a promising important addition to conventional stress echocardiography.
authors.affiliation: Section of Cardiology, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: S
authors.initials: S
authors.lastname: Shimoni
authors.forename: W A
authors.initials: WA
authors.lastname: Zoghbi
authors.forename: F
authors.initials: F
authors.lastname: Xie
authors.forename: D
authors.initials: D
authors.lastname: Kricsfeld
authors.forename: S
authors.initials: S
authors.lastname: Iskander
authors.forename: L
authors.initials: L
authors.lastname: Gobar
authors.forename: I A
authors.initials: IA
authors.lastname: Mikati
authors.forename: J
authors.initials: J
authors.lastname: Abukhalil
authors.forename: M S
authors.initials: MS
authors.lastname: Verani
authors.forename: E L
authors.initials: EL
authors.lastname: O'Leary
authors.forename: T R
authors.initials: TR
authors.lastname: Porter
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000418:Albumins / Q000627:therapeutic use; D003287:Contrast Media; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology; D025401:Echocardiography, Stress; D005240:Feasibility Studies; D005260:Female; D005466:Fluorocarbons / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D000418:Albumins; D003287:Contrast Media; C099458:FS 069; D005466:Fluorocarbons