title: Comparison of cardiac pacing modes in patients with chronic obstructive pulmonary disease.
abstract: OBJECTIVE
  This study compares the relative benefits of dual chamber adaptive rate pacing (DDDR) with ventricular adaptive rate pacing (VVIR) in patients with chronic obstructive pulmonary disease (COPD).
  
  
  METHODS
  Cardiac hemodynamics were evaluated with serial exercise tests. A minimum of 2 h was allowed between studies. Pulmonary gas exchange was measured and cardiac output (CO) was determined at rest and immediately after maximum exercise by Doppler echocardiography.
  
  
  METHODS
  Sixteen patients with DDDR pacemakers were studied. Eight patients had COPD and eight patients had normal lung function (NLF). Baseline lung function was documented with spirometry.
  
  
  METHODS
  The patients with NLF functioned as a control group. Prior to entry into the study, the rate-modulated parameters of the pacemaker were programmed to a clinically determined optimal set of parameters for each individual patient. These were not changed for the duration of the study.
  
  
  RESULTS
  Both groups showed a statistically significant improvement in exercise duration, CO at maximum exercise, and cardiac output difference (CODiff) with the dual chamber adaptive rate pacing mode (DDDR). (COdiff is the change in CO from rest to maximum exercise.) Patients with NLF also showed a significant improvement in anaerobic threshold (AT) and VCO2 max with DDDR. Patients with lung disease showed a statistically significant improvement at all levels of exercise in the ventilatory equivalent for oxygen.
  
  
  CONCLUSIONS
  In this study, those patients with chronic lung disease who required cardiac pacing performed significantly better in the DDDR mode as compared with the VVIR mode. Therefore, the DDDR pacing mode should provide an improved quality of life for the patient with COPD who also requires cardiac pacing.
authors.affiliation: Department of Medicine, Loma Linda University Medical Center, CA 92354.
authors.forename: R V
authors.initials: RV
authors.lastname: Jutzy
authors.forename: L
authors.initials: L
authors.lastname: Houston-Feenstra
authors.forename: P A
authors.initials: PA
authors.lastname: Levine
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015308:Anaerobic Threshold / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D001919:Bradycardia / Q000628:therapy; D002245:Carbon Dioxide / Q000378:metabolism; D002302:Cardiac Output / Q000502:physiology; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004867:Equipment Design; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008168:Lung / Q000502:physiology; D008173:Lung Diseases, Obstructive / Q000503:physiopathology*; D008297:Male; D008450:Maximal Midexpiratory Flow Rate / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D010138:Pacemaker, Artificial; D005082:Physical Exertion / Q000502:physiology; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012804:Sick Sinus Syndrome / Q000628:therapy; D013147:Spirometry; D014797:Vital Capacity / Q000502:physiology
chemical_list: D002245:Carbon Dioxide