title: [Association between severe obstructive sleep apnea syndrome and sinus dysfunction].
abstract: OBJECTIVE
  To preliminarily investigate the association between severe obstructive sleep apnea syndrome (OSAS) and sinus dysfunction (SD).
  
  
  METHODS
  From March of 2005 to June of 2006, 70 patients with severe OSAS and 36 simple snorers underwent electrocardiography by polysomnography. In order to compare their sinus function and analyse the risk factors of SD, atropine test with simultaneous monitoring of ultramicroelectrocardiogram (UMECG) was performed in those with the lowest heart rate < 40 pbm, or the highest sinus heart rate < 90 bpm, or the longest R-R interval > 2.0 seconds. All data were statistically analyzed with SPSS 13.0 software.
  
  
  RESULTS
  Sixteen of the 70 severe OSAS patients were diagnosed as with SD with an incidence of 22.9%, significantly higher than that in the patients with simple snore (2/36, 5.6%, P = 0.025). In 70 patients with severe OSAS (16 patients with SD), single factor analysis indicated that there was a significant difference between those with SD and those without SD in Nadir pulse oxygen saturation, longest apnea duration and incidence of coronary artery disease (T test, P = 0.002; T test, P = 0.029; Fisher's Exact test, P = 0.043), and Logistic regressive analysis showed that the risk factors of SD were the decrease of Nadir pulse oxygen saturation (P = 0.003, OR < 0.001, 95% CI 0.000 - 0.016) and age (P = 0.055, OR = 1.053, 95% CI 1.007 - 1.125).
  
  
  CONCLUSIONS
  The incidence of SD in patients with severe OSAS is higher than that in simple snore. Lower Nadir pulse oxygen saturation during sleep was the major risk factor for occurrence of SD in patients with severe OSAS.
authors.affiliation: Department of Respiratory Medicine, First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.forename: Xi-long
authors.initials: XL
authors.lastname: Zhang
authors.forename: Yu-ying
authors.initials: YY
authors.lastname: Cai
authors.forename: Ling
authors.initials: L
authors.lastname: Hu
authors.forename: Chong
authors.initials: C
authors.lastname: Li
mesh_terms: D000328:Adult; D003324:Coronary Artery Disease / Q000209:etiology / Q000503:physiopathology; D004562:Electrocardiography; D006339:Heart Rate; D006801:Humans; D008875:Middle Aged; D017286:Polysomnography; D012307:Risk Factors; D012848:Sinoatrial Block / Q000209:etiology / Q000503:physiopathology; D012849:Sinoatrial Node / Q000503:physiopathology*; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000503:physiopathology*; D012913:Snoring / Q000209:etiology / Q000503:physiopathology