title: Feasibility of measuring coronary flow velocity and reserve in the left anterior descending coronary artery by transthoracic Doppler echocardiography in a relatively obese American population.
abstract: BACKGROUND
  Transthoracic Doppler echocardiography (TTDE) assessment of coronary flow velocity reserve (CFVR) has been validated in Asian and European centers. This methodology has not gained acceptability in the United States due to the bias that coronary flow velocity (CFV) by TTDE might be difficult in an obese population with relatively poor acoustic windows.
  
  
  METHODS
  Baseline CFV in the left anterior descending coronary artery (LAD) by TTDE was obtained in 67 nonselected American patients. A subset of 38/67 received adenosine infusion for measuring CFVR of the LAD.
  
  
  OBJECTIVE
  The aim of this study was twofold: (1) to determine the feasibility of measuring CFV and CFVR in the LAD by TTDE in a relatively obese American population, and (2) to compare CFV and CFVR values in this population with those previously obtained in a group of Japanese patients.
  
  
  RESULTS
  The mean body mass index (BMI) of the American population (28 +/- 6 kg/m2, range: 18-46 kg/m2) was significantly higher than that of the Japanese group (23 +/- 4 kg/m2, range: 15-37 kg/m2). Twenty-five American patients were classified as obese (BMI >30 kg/m2). Baseline CFV was obtained in 60/67 patients (feasibility: 90%) with a 10% need for intravenous contrast agent to enhance the delineation of the CFV envelope. The success rate in recording CFVR in American patients (92%) was nearly identical to that of a Japanese group (99%). The time-averaged peak diastolic coronary flow velocity increased from 15.6 +/- 5.5 cm/sec at baseline to 47.1 +/- 17.9 cm/sec during adenosine infusion, and CFVR was calculated to be 3.22 +/- 1.15 (range: 0.94-5.69). Intraobserver and interobserver variability for the CFV recording was 4.7 and 6.2%, respectively.
  
  
  CONCLUSIONS
  These results suggest that the noninvasive measurement of CFV and CFVR of the LAD is feasible even in a relatively obese American population. Furthermore, the success rates for recording CFV and CFVR are similar to those measured in a Japanese population. This methodology has the potential to provide useful physiological information on the coronary circulation in American patients.
authors.affiliation: Department of Internal Medicine, Tane General Hospital, Osaka, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Lodato
authors.forename: Kathy T
authors.initials: KT
authors.lastname: Furlong
authors.forename: Roberto M
authors.initials: RM
authors.lastname: Lang
authors.forename: Junichi
authors.initials: J
authors.lastname: Yoshikawa
mesh_terms: D000241:Adenosine / Q000008:administration & dosage; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity / Q000502:physiology*; D015992:Body Mass Index; D003287:Contrast Media; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D015150:Echocardiography, Doppler / Q000379:methods*; D018618:Echocardiography, Doppler, Color; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007564:Japan; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014481:United States; D014665:Vasodilator Agents / Q000008:administration & dosage
chemical_list: D003287:Contrast Media; D014665:Vasodilator Agents; D000241:Adenosine