title: Ultrasonographic assessment of basal coronary flow as a screening tool to exclude significant left anterior descending coronary artery stenosis.
abstract: OBJECTIVE
  Coronary blood flow exhibits a biphasic pattern at rest with a higher diastolic and a smaller systolic component. In the present investigation, we evaluated whether a decreased diastolic to systolic velocity ratio of basal coronary flow may be useful in the identification of subjects with significant left anterior descending coronary artery (LAD) stenosis.
  
  
  METHODS
  One hundred and twenty-nine consecutive patients (62 with unstable angina, 25 with acute myocardial infarction and 42 with chronic coronary artery disease) were included in the study. Blood flow velocities were recorded in the mid-distal portion of the LAD using an ATL 5000 CV HDI ultrasound system. All patients underwent coronary angiography and were divided into two groups according to the absence (group 1) or the presence (group 2) of significant LAD stenosis (lumen narrowing > or = 70%). In 60 of the 129 patients, coronary flow reserve was evaluated non-invasively.
  
  
  RESULTS
  Adequate Doppler recordings in the LAD were obtained by transthoracic echocardiography in 113 patients. There were no differences between groups with regard to sex, cardiovascular risk factors, left ventricular mass and volumes, ejection fraction, whereas the diastolic to systolic velocity ratio of basal coronary flow was significantly lower in group 2 patients (1.41 +/- 4.7 vs. 2.08 +/- 0.64, P < 0.00001). The receiver operating characteristic curve showed that a diastolic to systolic velocity ratio < 1.6 had a sensitivity of 77%, a specificity of 91%, a positive predictive value of 77%, a negative predictive value of 97%, and a diagnostic accuracy of 84% for the presence of significant LAD stenosis. In 55/60 patients, results of basal coronary flow and coronary flow reserve were concordant. On multivariate logistic regression analysis, the diastolic to systolic velocity ratio was a strong independent predictor of LAD stenosis > or = 70% (odds ratio 4.90, 95% confidence interval 1.65-7.30).
  
  
  CONCLUSIONS
  The present findings suggest that assessment of basal coronary flow in the LAD may be useful to rule out the presence of significant stenosis.
authors.affiliation: Division of Cardiology, S Maria di Loreto Hospital, Naples, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Accadia
authors.forename: Luigi
authors.initials: L
authors.lastname: Ascione
authors.forename: Mario
authors.initials: M
authors.lastname: De Michele
authors.forename: Antonello
authors.initials: A
authors.lastname: D'Andrea
authors.forename: Salvatore
authors.initials: S
authors.lastname: Rumolo
authors.forename: Cosimo
authors.initials: C
authors.lastname: Sacra
authors.forename: Marino
authors.initials: M
authors.lastname: Scherillo
authors.forename: Bernardino
authors.initials: B
authors.lastname: Tuccillo
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000502:physiology*; D003971:Diastole / Q000502:physiology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012039:Regional Blood Flow; D012680:Sensitivity and Specificity; D013599:Systole / Q000502:physiology; D018608:Ultrasonography, Doppler