title: Effect of beta-blocker therapy on heart rate response in patients with hypertension and newly diagnosed untreated obstructive sleep apnea syndrome.
abstract: BACKGROUND
  Beta1-receptor antagonists (BBs) are commonly administered in the treatment of cardiovascular disease (CVD). The reported benefits of BB use in CVD patients with concomitant obstructive sleep apnea (OSA) may be limited by their impact on apnea-induced bradycardias. Therefore the aim of the study was to test the influence of BBs on periapneic heart rate (HR) fluctuations in hypertensive patients with newly-detected and untreated OSA.
  
  
  METHODS
  We studied 88 hypertensive patients (56 on BBs and 32 BB naive) with newly-diagnosed moderate-to-severe OSA who were free of major pulmonary comorbidities and did not require antiarrhythmic therapy. ECGs recorded during sleep were investigated for heart rate (HR) responses to apneas allowing to compare extreme HR accelerations and decelerations between the groups.
  
  
  RESULTS
  Average sleep-time HR was comparable in BB-naive (BB-) and BB-treated (BB+) patients. Direct comparisons showed that HR decelerations were also similar in the two subgroups (53.8±9.6 vs. 54.4±7.8 bpm; P=0.78, for BB- and BB+, respectively) however, BBs blunted the OSA-induced HR accelerations (82.3±12.2 vs. 74.3±10.0; P=0.003). After adjusting for baseline HR and magnitude of desaturations, HR decelerations were more evident in BB-naive group whereas tachycardic responses remained blunted in the BB+ group. The incidence of ectopies and conduction abnormalities were comparable across two groups.
  
  
  CONCLUSIONS
  Beta-blockers do not potentiate apnea-induced HR decelerations, attenuate apnea-induced increases in heart rate and do not influence incidence of ectopies and conduction abnormalities in patients with hypertension and moderate-to-severe, untreated OSA.
authors.affiliation: Department of Hypertension and Diabetology, Medical University of Gdańsk, Gdańsk, Poland; Department of Cardiovascular Diseases, International Clinical Research Center, St. Anne's University Hospital in Brno (FNUSA), Brno, Czech Republic. Electronic address: lupus@gumed.edu.pl.
authors.forename: Jacek
authors.initials: J
authors.lastname: Wolf
authors.affiliation: Department of Pneumonology and Allergology, Medical University of Gdańsk, Gdańsk, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Drozdowski
authors.affiliation: Department of Hypertension and Diabetology, Medical University of Gdańsk, Gdańsk, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Czechowicz
authors.affiliation: Institute of Human Physiology, Medical University of Gdańsk, Gdańsk, Poland.
authors.forename: Paweł J
authors.initials: PJ
authors.lastname: Winklewski
authors.affiliation: Department of Pneumonology and Allergology, Medical University of Gdańsk, Gdańsk, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Jassem
authors.affiliation: Department of Cardiovascular Diseases, International Clinical Research Center, St. Anne's University Hospital in Brno (FNUSA), Brno, Czech Republic; Divisions of Cardiovascular Diseases and Hypertension, Mayo Clinic, Rochester, MN, USA; Department of Cardiology, University Hospital Olomouc, Czech Republic.
authors.forename: Tomas
authors.initials: T
authors.lastname: Kara
authors.affiliation: Divisions of Cardiovascular Diseases and Hypertension, Mayo Clinic, Rochester, MN, USA.
authors.forename: Virend K
authors.initials: VK
authors.lastname: Somers
authors.affiliation: Department of Hypertension and Diabetology, Medical University of Gdańsk, Gdańsk, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Narkiewicz
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage*; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D004562:Electrocardiography / Q000187:drug effects*; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012189:Retrospective Studies; D012890:Sleep / Q000502:physiology*; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology
chemical_list: D000319:Adrenergic beta-Antagonists
keywords: Beta-blockers; Bradycardia; Heart rate control; Obstructive sleep apnea; Tachycardia