title: Clinical and echocardiographic parameters associated with low chronotropic index in non-elderly patients.
abstract: BACKGROUND
  Despite abundant evidence of increased morbidity and mortality, chronotropic incompetence (CI) is not a routine diagnosis well defined in protocols of cardiac evaluation and its clinical importance is still underestimated.
  
  
  OBJECTIVE
  To evaluate the clinical and echocardiographic parameters associated with HF in non-elderly patients submitted to stress echocardiography (SE).
  
  
  METHODS
  One thousand seven hundred ninety-eight patients with a mean age of 48.4 ± 7.5 years, who underwent SE between January/2000 and August/2009 were evaluated. Patients with chronotropic index smaller than 0.8 were considered chronotropic incompetent as compared to competent patients as to clinical and echocardiographic characteristics.
  
  
  RESULTS
  The duration of the exercise was 9.3 ± 2.4 minutes on average. Two hundred and seventy (15%) patients were chronotropic incompetent. The chronotropic index of this group was 0.7 ± 0.1 vs. 1.0 ± 0.1 for competent patients. Multivariate logistic regression analysis identified the following parameters as independently associated with HF: dyspnea on examination [odds ratio (OR) = 4.27, p <0.0001], previous chest pain on medical history (OR = 1.51; p = 0.0111), higher left ventricular mass rate in incompetent patients (LVMI) (OR = 1.16, p = 0.0001), metabolic equivalents (METs) (OR = 0.70, p = 0 , 0001), ST segment depression (OR = 0.58, p = 0.0003) and high systolic blood pressure (ΔSBP) (OR = 0.87, p = 0.0011). Myocardial ischemia was not associated with HF.
  
  
  CONCLUSIONS
  HF is associated with functional parameters, such as dyspnea on exertion, history of chest pain and lower METS. It is also associated with structural benchmark index of left ventricular mass. In addition, chronotropic incompetence does not appear to increase the chance of myocardial ischemia in non-elderly patients.
authors.affiliation: Universidade Federal de Sergipe, São Cristovão, Brazil.
authors.forename: Paulo Fernando Carvalho
authors.initials: PF
authors.lastname: Secundo
authors.forename: Bruno Fernandes de Oliveira
authors.initials: BF
authors.lastname: Santos
authors.forename: José Alves
authors.initials: JA
authors.lastname: Secundo Júnior
authors.forename: Joiciane Bárbara da
authors.initials: JB
authors.lastname: Silva
authors.forename: Adriana Ribeiro de
authors.initials: AR
authors.lastname: Souza
authors.forename: Gustavo Baptista de Almeida
authors.initials: GB
authors.lastname: Faro
authors.forename: José Augusto
authors.initials: JA
authors.lastname: Barreto-Filho
authors.forename: Antônio Carlos Sobral
authors.initials: AC
authors.lastname: Sousa
authors.forename: Joselina Luzia Menezes
authors.initials: JL
authors.lastname: Oliveira
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D025401:Echocardiography, Stress / Q000379:methods*; D004812:Epidemiologic Methods; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000503:physiopathology; D012016:Reference Values; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology; D055815:Young Adult