title: Predictors of chronotropic incompetence in the pacemaker patient population.
abstract: OBJECTIVE
  We prospectively evaluated results from cardiopulmonary exercise testing for chronotropic incompetence (CI) in a cohort of 292 pacemaker patients. In addition, we evaluated comorbidity and antiarrhythmic patient data as indicators of CI.
  
  
  RESULTS
  On the basis of exercise stress testing and application of the definition of CI by Wilkoff, 51% of our cohort was categorized as having CI. Indications for pacemaker implant for this patient group were 42% atrioventricular block, 56% sinus node disease, and 59% atrial fibrillation. Maximum oxygen uptake (VO(2) max) and exercise duration were significantly reduced among CI pacemaker patients, whereas oxygen uptake at the anaerobic threshold remained unchanged. The following clinical characteristics were significant predictors of CI: existence of coronary artery disease (P = 0.038), presence of an acquired valvular heart disease (P = 0.037), and former cardiac surgery (P = 0.041). Age, gender, arterial hypertension, cardiomyopathy, congenital heart disease, left ventricular ejection fraction, and time period between stress-exercise examination and pacemaker implantation were not significant predictors of CI. Chronic antiarrhythmic therapy with digitalis (P = 0.013), beta blockers (P = 0.036), and amiodarone (P = 0.045) were significant predictors of CI. In contrast, medication with class I and IV antiarrhythmics had no significant correlation with CI.
  
  
  CONCLUSIONS
  We found the following characteristics predictive of CI in this pacemaker patient population: VO(2) max, existence of coronary artery disease or acquired valvular heart disease, previous cardiac surgery, as well as medication with digitalis, beta blockers, and amiodarone.
authors.affiliation: Charité-Campus Mitte, Medizinische Klinik mit Schwerpunkt Kardiologie Angiologie, Pneumologie, Schumannstrasse 20/21, D-10117 Berlin, Germany. christoph.melzer@charite.de
authors.forename: C
authors.initials: C
authors.lastname: Melzer
authors.forename: J
authors.initials: J
authors.lastname: Witte
authors.forename: R
authors.initials: R
authors.lastname: Reibis
authors.forename: H J
authors.initials: HJ
authors.lastname: Bondke
authors.forename: W
authors.initials: W
authors.lastname: Combs
authors.forename: K
authors.initials: K
authors.lastname: Stangl
authors.forename: G
authors.initials: G
authors.lastname: Baumann
authors.forename: H
authors.initials: H
authors.lastname: Theres
mesh_terms: D001281:Atrial Fibrillation / Q000503:physiopathology / Q000628:therapy; D015897:Comorbidity; D005080:Exercise Test; D005260:Female; D006327:Heart Block / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D010138:Pacemaker, Artificial; D010807:Physical Endurance; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012044:Regression Analysis; D012804:Sick Sinus Syndrome / Q000503:physiopathology / Q000628:therapy; D012849:Sinoatrial Node / Q000503:physiopathology*