title: Assessment of coronary flow reserve by adenosine transthoracic echocardiography: validation with intracoronary Doppler.
abstract: OBJECTIVE
  Data on the accuracy of transthoracic echocardiographic (TTE) analysis of coronary flow reserve are scarce. We compared coronary flow reserve measurements assessed using TTE with those achieved using the gold standard of intracoronary Doppler.
  
  
  METHODS
  Twenty-one patients admitted for elective coronary angioplasty to the circumflex or left anterior descending (LAD) coronary artery underwent TTE immediately before angioplasty, both at rest and during intravenous administration of adenosine 140 microg/kg/min. Transthoracic images of distal LAD coronary diameter and coronary flow were obtained in 14 patients (66%). These patients then underwent intracoronary Doppler analysis of coronary flow reserve in the distal LAD coronary artery. In 1 patient with a proximal LAD artery lesion, the narrowing could not be crossed with the Doppler guidewire. Paired data on coronary flow reserve were therefore available in 13 patients.
  
  
  RESULTS
  Patients were aged 61.7 +/- 8.3 years. Ten were men. Body mass index was 26.3 +/- 4.6 kg/m(2). Resting distal LAD artery blood flow was 18.4 +/- 9.0 mL/min assessed by TTE versus 17.6 +/- 8.1 mL/min by intracoronary Doppler. Hyperemic flow was 36.3 +/- 23.4 versus 33.1 +/- 19.2 mL/min, respectively. Coronary flow reserve was therefore 1.89 +/- 0.66 by TTE compared with 1.83 +/- 0.62 by intracoronary Doppler. Limits of agreement for coronary flow reserve were -0.28 to +0.44, well within boundaries of clinical acceptability.
  
  
  CONCLUSIONS
  Transthoracic echocardiography is capable of providing accurate data on coronary flow reserve in the distal LAD coronary artery. As a truly noninvasive modality, this technique offers advantages over traditional invasive procedures.
authors.affiliation: Cardiac Unit, Papworth Hospital, Cambridge CB3 8RE, UK. djrhs@waitrose.com
authors.forename: David J R
authors.initials: DJ
authors.lastname: Hildick-Smith
authors.forename: Richard
authors.initials: R
authors.lastname: Maryan
authors.forename: Leonard M
authors.initials: LM
authors.lastname: Shapiro
mesh_terms: D000241:Adenosine; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D001783:Blood Flow Velocity / Q000502:physiology; D003287:Contrast Media; D003326:Coronary Circulation; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000628:therapy; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D003287:Contrast Media; D000241:Adenosine