title: Nocturnal cardiac arrhythmia in patients with obstructive sleep apnea.
abstract: OBJECTIVE
  Nocturnal cardiac arrhythmias occur in patients with obstructive sleep apnea (OSA), reportedly as a consequence of the autonomic effects of recurrent apnea with subsequent oxygen desaturation. We have investigated whether different patterns of OSA are associated with specific arrhythmia during sleep.
  
  
  METHODS
  Electrocardiographic (ECG) data recorded during polysomnography (PSG) were analysed in 257 consecutive OSA patients to determine the prevalence of cardiac rhythm disturbances, and to relate these to breathing pattern (normal, apnea/hypopnea, recovering ventilation, snoring) and oxygen saturation.
  
  
  RESULTS
  Arrhythmias were found in 18.5% of patients. Patients with nocturnal bradyarrhythmia (BA) had higher values of ventilatory disturbance (apnea-hypopnea index [AHI] 58.8+/-36.8 vs 37.2+/-30.3, p=0.02), mean desaturation amplitude (8.9+/-4 vs 5.9+/-3.4%, p=0.03), and a lower SaO(2) nadir (69% vs 77%, p=0.003) than those without arrhythmia. The prevalence of BA in patients with AHI>or=30/h was significantly higher than that observed in those with AHI<30/h (7.8% vs 1.5%, respectively; chi(2)=5.61, p=0.01). In contrast, patients with tachyarrhythmia (TA) had no significant differences in AHI, mean desaturation amplitude or SaO(2) nadir than those without arrhythmia. No associations were found between arrhythmia and the presence of comorbidity or concomitant medical therapy, except for an association between tachyarrhythmia and chronic obstructive pulmonary disease (COPD) (odds ratio 2.53; 95% confidence intervals 1.1-5.8, p=0.03).
  
  
  CONCLUSIONS
  We conclude that while BA during sleep is associated with OSA severity, concomitant COPD or beta(2)-treatment may play a role in the development of TA during sleep.
authors.affiliation: Divisione di Cardiologia, Istituto Scientifico di Montescano, Fondazione S. Maugeri, IRCCS, Pavia, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Olmetti
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: La Rovere
authors.forename: Elena
authors.initials: E
authors.lastname: Robbi
authors.forename: Anna Eugenia
authors.initials: AE
authors.lastname: Taurino
authors.forename: Francesco
authors.initials: F
authors.lastname: Fanfulla
mesh_terms: D000318:Adrenergic beta-Agonists / Q000009:adverse effects; D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000503:physiopathology; D001341:Autonomic Nervous System / Q000503:physiopathology*; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000150:complications / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D017286:Polysomnography; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000503:physiopathology; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000503:physiopathology; D012913:Snoring / Q000503:physiopathology
chemical_list: D000318:Adrenergic beta-Agonists; D010100:Oxygen