title: Coronary flow velocity reserve during dobutamine stress echocardiography.
abstract: BACKGROUND
  A coronary flow velocity reserve (CFVR)≥2 is adequate to infer a favorable prognosis or the absence of significant coronary artery disease.
  
  
  OBJECTIVE
  To identify parameters which are relevant to obtain CFVR (adequate or inadequate) in the left anterior descending coronary artery (LAD) during dobutamine stress echocardiography (DSE).
  
  
  METHODS
  100 patients referred for detection of myocardial ischemia by DSE were evaluated; they were instructed to discontinue the use of β-blockers 72 hours prior to the test. CFVR was calculated as a ratio of the diastolic peak velocity (cm/s) (DPV) on DSE (DPV-DSE) to baseline DPV at rest (DPV-Rest). In group I, CFVR was <2 and, in group II, CFVR was ≥2. The Fisher's exact test and Student's t test were used for the statistical analyses. P values<0.05 were considered statistically significant.
  
  
  RESULTS
  At rest, the time (in seconds) to obtain Doppler in LAD in groups I and II was not different (53±31 vs. 45±32; p=0.23). During DSE, LAD was recorded in 92 patients. Group I patients were older (65.9±9.3 vs. 61.2±10.8 years; p=0.04), had lower ejection fraction (61±10 vs. 66±6%; p=0.005), higher DPV-Rest (36.81±08 vs. 25.63±06 cm/s; p<0.0001) and lower CFVR (1.67±0.24 vs. 2.53±0.57; p<0.0001), but no difference was observed regarding DPVDSE (61.40±16 vs. 64.23±16 cm/s; p=0.42). β-blocker discontinuation was associated with a 4-fold higher chance of a CFVR<2 (OR= 4; 95% CI [1.171-13.63], p=0.027).
  
  
  CONCLUSIONS
  DPV-Rest was the main parameter to determine an adequate CFVR. β-blocker discontinuation was significantly associated with inadequate CFVR. The high feasibility and the time to record the LAD corroborate the use of this methodology.
authors.affiliation: Prontocardio - Pronto Atendimento Cardiologico SC Ltda, Fortaleza, CE, Brasil.
authors.forename: José Sebastião de
authors.initials: JS
authors.lastname: Abreu
authors.affiliation: Universidade Estadual do Ceara, Fortaleza, CE, Brasil.
authors.forename: José Wellington Oliveira
authors.initials: JW
authors.lastname: Lima
authors.affiliation: Prontocardio - Pronto Atendimento Cardiologico SC Ltda, Fortaleza, CE, Brasil.
authors.forename: Tereza Cristina Pinheiro
authors.initials: TC
authors.lastname: Diógenes
authors.affiliation: Faculdade de Medicina, Universidade Federal do Ceara, Fortaleza, CE, Brasil.
authors.forename: Jordana Magalhães
authors.initials: JM
authors.lastname: Siqueira
authors.affiliation: Faculdade de Medicina, Universidade Federal do Ceara, Fortaleza, CE, Brasil.
authors.forename: Nayara Lima
authors.initials: NL
authors.lastname: Pimentel
authors.affiliation: Faculdade de Medicina, Universidade Federal do Ceara, Fortaleza, CE, Brasil.
authors.forename: Pedro Sabino
authors.initials: PS
authors.lastname: Gomes Neto
authors.affiliation: Prontocardio - Pronto Atendimento Cardiologico SC Ltda, Fortaleza, CE, Brasil.
authors.forename: Marília Esther Benevides de
authors.initials: ME
authors.lastname: Abreu
authors.affiliation: Prontocardio - Pronto Atendimento Cardiologico SC Ltda, Fortaleza, CE, Brasil.
authors.forename: José Nogueira
authors.initials: JN
authors.lastname: Paes Júnior
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D003326:Coronary Circulation / Q000502:physiology*; D003430:Cross-Sectional Studies; D015150:Echocardiography, Doppler / Q000379:methods; D025401:Echocardiography, Stress / Q000379:methods*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D015203:Reproducibility of Results; D012307:Risk Factors; D013318:Stroke Volume / Q000502:physiology; D013997:Time Factors