title: Effect of Nocturnal Intermittent Hypoxia on Left Atrial Appendage Flow Velocity in Atrial Fibrillation.
abstract: BACKGROUND
  The mechanism underlying the associations of sleep-disordered breathing (SDB) with stroke and atrial fibrillation (AF) is not well established. We explored the relationship between nocturnal intermittent hypoxia, a marker of SDB, and left atrial (LA)/LA appendage (LAA) function among AF patients.
  
  
  METHODS
  We evaluated 134 consecutive AF candidates for catheter ablation (age, 59.6 ± 9.4 years; body mass index [BMI], 24.8 ± 3.2; Congestive Heart Failure, Hypertension, Age (≥75 years), Diabetes, Stroke/Transient Ischemic Attack, Vascular Disease, Age (65-74 years), Sex (Female) (CHA2DS2-VASc) score, 1.2 ± 1.1, paroxysmal AF, n = 83) using nocturnal pulse oximetry, a noninvasive screening method for nocturnal intermittent hypoxia. Based on 3% oxygen desaturation index (3% ODI), patients were divided into nocturnal intermittent hypoxia (3% ODI > 15; n = 32) and control groups (3% ODI ≤ 15; n = 102).
  
  
  RESULTS
  The nocturnal intermittent hypoxia group demonstrated significantly higher weight, BMI, Congestive Heart Failure, Hypertension, Age, Diabetes, Stroke/Transient Ischemic Attack (CHADS2) and CHA2DS2-VASc scores, serum hemoglobin A1c and plasma brain natriuretic peptide levels, LA size, and prevalence of hypertension, vascular disease, and sick sinus syndrome. Echocardiographically, nocturnal intermittent hypoxia was associated with a higher grade of spontaneous echo contrast and low LAA flow velocity. Multiple regression analysis adjusted for type of AF, CHA2DS2-VASc score, BMI, plasma brain natriuretic peptide level, LA size, and rhythm on echocardiography revealed that 3% ODI was a factor independently associated with LAA flow velocity (β = -0.184; 95% confidence interval, -0.818 to -0.006).
  
  
  CONCLUSIONS
  Nocturnal intermittent hypoxia was an independent determinant for low LAA flow velocity in patients with AF, suggesting that the connection between SDB and LAA function might underlie the association of AF with stroke.
authors.affiliation: Division of Cardiology, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Kimura
authors.affiliation: Division of Cardiology, Department of Medicine, Keio University School of Medicine, Tokyo, Japan. Electronic address: kohno.a2@keio.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kohno
authors.affiliation: Division of Cardiology, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Nakajima
authors.affiliation: Division of Cardiology, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Kashimura
authors.affiliation: Division of Cardiology, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Katsumata
authors.affiliation: Division of Cardiology, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Nishiyama
authors.affiliation: Division of Cardiology, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Nishiyama
authors.affiliation: Division of Cardiology, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Tanimoto
authors.affiliation: Division of Cardiology, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Yoshiyasu
authors.initials: Y
authors.lastname: Aizawa
authors.affiliation: Division of Cardiology, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Fukuda
authors.affiliation: Division of Cardiology, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Takatsuki
mesh_terms: D000368:Aged; D020517:Atrial Appendage / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001281:Atrial Fibrillation / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D016279:Atrial Function, Left / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D000860:Hypoxia / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D012039:Regional Blood Flow / Q000502:physiology*; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012891:Sleep Apnea Syndromes / Q000150:complications* / Q000503:physiopathology; D014463:Ultrasonography