title: Chronotropic incompetence and coronary artery disease.
abstract: OBJECTIVE
  Although chronotropic incompetence (CI) represents an independent predictor of mortality and incidence of coronary artery disease, its pathophysiological mechanisms remain unknown. The purpose of this investigation was to evaluate wall motion abnormalities of the left ventricle and location of coronary arterial lesions in patients with and without CI.
  
  
  METHODS
  After exclusion of confounding factors, 610 patients (mean age of 58.4 +/- 11 years; 275 men) with ischaemia who underwent exercise echocardiography were studied. Based on heart rate (HR) reached in treadmill testing, patients were divided into two groups: Chl (97 patients who did not reach 85% of maximum HR recommended for age) and ChC (513 patients who achieved 85% of the maximum age-predicted HR).
  
  
  RESULTS
  There was a higher frequency of dyspnoea (5.2% vs. 0.6%, P = 0.003), systemic hypertension (69.1% vs. 57.3%, P = 0.031) and obesity (38.1% vs. 22.6%, P = 0.001), and a lower tolerance to effort (dyspnoea as limitation of physical effort: 36.1% vs. 8.0%, P < 0.0001; duration of treadmill test: 4.4 +/- 2.2 vs. 7.2 +/- 2.8, P < 0.0001; METs: 6.0 +/- 2.6 vs. 8.4 +/- 2.9, P = 0.002) in Chl compared to ChC. The wall motion score index (WMSI) was higher in Chl than in ChC, both at rest (1.15 +/- 0.29 vs. 1.07 +/- 0.19, P = 0.011) and after exercise (1.24 +/- 0.29 vs. 1.15 +/- 0.19, P = 0.002). Systolic function, which was evaluated in peak exercise through WMSI, was significantly more altered in the Chl group. The presence of severe injuries in right coronary was independently associated with CI (adjusted OR = 3.57, CI 95%: 1.86-6.87).
  
  
  CONCLUSIONS
  Chronotropic incompetence is associated with ventricular dysfunction in peak exercise and critical right coronary artery lesions.
authors.affiliation: Department of Internal Medicine, Cardiology Division of Federal University of Sergipe, Sergipe, Brazil.
authors.forename: Fernando Diego
authors.initials: FD
authors.lastname: Anjos-Andrade
authors.forename: Antônio Carlos Sobral
authors.initials: AC
authors.lastname: Sousa
authors.forename: José Augusto Soares
authors.initials: JA
authors.lastname: Barreto-Filho
authors.forename: Erica Oliveira
authors.initials: EO
authors.lastname: Alves
authors.forename: Adão Cardoso
authors.initials: AC
authors.lastname: Nascimento-Júnior
authors.forename: Nathalie Oliveira
authors.initials: NO
authors.lastname: de Santana
authors.forename: Francis Lima
authors.initials: FL
authors.lastname: de Vasconcelos
authors.forename: Flávia Barreto
authors.initials: FB
authors.lastname: Garcez
authors.forename: Vanessa Porto
authors.initials: VP
authors.lastname: de Araujo
authors.forename: Ana Carla Pereira
authors.initials: AC
authors.lastname: de Araujo
authors.forename: Bruno Fernandes de Oliveira
authors.initials: BF
authors.lastname: Santos
authors.forename: Débora Consuelo Rocha
authors.initials: DC
authors.lastname: Silveira
authors.forename: Rívia Siqueira
authors.initials: RS
authors.lastname: Amorim
authors.forename: Diego Leonardo Cruz Lima
authors.initials: DL
authors.lastname: Garcia
authors.forename: José Carlos Sizino
authors.initials: JC
authors.lastname: Franco Filho
authors.forename: Antônio Aristides
authors.initials: AA
authors.lastname: de Sá Neto
authors.forename: Flávia Ricci
authors.initials: FR
authors.lastname: Calasans
authors.forename: Enaldo Vieira
authors.initials: EV
authors.lastname: de Melo
authors.forename: Joselina Luzia Menezes
authors.initials: JL
authors.lastname: Oliveira
mesh_terms: D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000503:physiopathology*; D004417:Dyspnea / Q000150:complications; D004452:Echocardiography; D004562:Electrocardiography; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006439:Hemodynamics; D006801:Humans; D006973:Hypertension / Q000150:complications; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D012044:Regression Analysis; D018754:Ventricular Dysfunction / Q000503:physiopathology*