title: Chronotropic incompetence and a higher frequency of myocardial ischemia in exercise echocardiography.
abstract: BACKGROUND
  Exercise echocardiography (EE) is an established method to diagnose coronary artery disease (CAD). Chronotropic incompetence (CI) during the EE may be a marker of myocardial ischemia. The purpose of this investigation was to evaluate the additive value of CI during EE in CAD diagnosis.
  
  
  METHODS
  Between 2000 and 2006, 4042 patients (1900 men with a mean age of 56 +/- 11 years) were evaluated by EE. Based on the heart rate (HR) reached during the exercise test, the subjects were divided into two groups: G1 group - 490 patients who failed to achieve 85% of the maximal age-predicted HR, and G2 group - 3552 patients who were able to achieve 85% of the maximal age-predicted HR. Clinical characteristics, left ventricular wall motion abnormalities - wall motion score index (WMSI) - and coronary angiography (CA) were the parameters compared between the two groups.
  
  
  RESULTS
  The left ventricular wall motion abnormalities were more frequent in G1 group than in G2 group (54% versus 26%; P < 0.00001). WMSI was higher in G1 group than in G2 group, both at rest (1.06 +/- 0.17 versus 1.02 +/- 0.09; P < 0.0001) and after exercise (1.12 +/- 0.23 versus 1.04 +/- 0.21; P < 0.0001). In G1 group, 82% of the patients with positive EE for myocardial ischemia presented obstructive coronary, compared to 71% (P = 0.03) in G2 group.
  
  
  CONCLUSIONS
  CI is associated with a higher frequency of myocardial ischemia during EE, reinforcing the concept that CI is a marker of the severity of myocardial ischemia.
authors.affiliation: Department of Internal Medicine, Cardiology Division, Federal University of Sergipe, Aracaju, Sergipe, Brazil. joselinasergipe@ig.com.br
authors.forename: Joselina L M
authors.initials: JL
authors.lastname: Oliveira
authors.forename: Thiago J S
authors.initials: TJ
authors.lastname: Góes
authors.forename: Thaiana A
authors.initials: TA
authors.lastname: Santana
authors.forename: Thiago F
authors.initials: TF
authors.lastname: Travassos
authors.forename: Lívia D
authors.initials: LD
authors.lastname: Teles
authors.forename: Fernando D
authors.initials: FD
authors.lastname: Anjos-Andrade
authors.forename: Adão C
authors.initials: AC
authors.lastname: Nascimento-Júnior
authors.forename: Erica O
authors.initials: EO
authors.lastname: Alves
authors.forename: Martha A
authors.initials: MA
authors.lastname: Barreto
authors.forename: José A
authors.initials: JA
authors.lastname: Barreto-Filho
authors.forename: Argemiro
authors.initials: A
authors.lastname: D'Oliveira
authors.forename: Antônio C S
authors.initials: AC
authors.lastname: Sousa
mesh_terms: D001145:Arrhythmias, Cardiac / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D001938:Brazil / Q000453:epidemiology; D015897:Comorbidity; D004452:Echocardiography / Q000706:statistics & numerical data*; D005080:Exercise Test / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D006339:Heart Rate; D006801:Humans; D015994:Incidence; D008297:Male; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012680:Sensitivity and Specificity