title: Intrathoracic pressure swings induced by simulated obstructive sleep apnoea promote arrhythmias in paroxysmal atrial fibrillation.
abstract: OBJECTIVE
  There is preliminary evidence for a link between obstructive sleep apnoea (OSA) and arrhythmias such as paroxysmal atrial fibrillation (PAF) and sudden cardiac death but underlying mechanisms remain largely unknown.
  
  
  RESULTS
  In this interventional crossover study, we evaluated whether intrathoracic pressure changes, induced by simulated OSA, trigger premature cardiac beats, and alter measures of ventricular repolarization [QTc and Tpeak-to-Tend (TpTec) intervals] in patients with PAF. 12-Lead-electrocardiograms were recorded continuously in 44 patients, while simulating obstructive apnoea (Mueller manoeuvre, MM), obstructive hypopnoea (inspiration through a threshold load, ITH), end-expiratory central apnoea (AP), and during normal breathing (NB) in randomized order. The prevalence of OSA in these 44 patients was assessed by a sleep study. Atrial premature beats (APBs) occurred more frequently during MM (55% of patients) and ITH (32%), but not during AP (14%), compared with NB (9%) (P < 0.001, P = 0.006 and P = 0.688, respectively). Mueller manoeuvre led to a significant prolongation of QTc and TpTec intervals (+17.3 ms, P < 0.001 and +4.3 ms, P = 0.005). Inspiration through a threshold load significantly increased QTc (+9.6 ms, P < 0.001) but not TpTec. End-expiratory central apnoea did not alter QTc and TpTec intervals. According to the sleep study, 56% of patients had OSA (apnoea hypopnoea index ≥5).
  
  
  CONCLUSIONS
  Simulated OSA induces APBs which may be important in patients with PAF, because the majority of episodes of PAF has been shown to be triggered by APBs. Simulated OSA leads to a significant prolongation of ventricular repolarization.
authors.affiliation: Sleep Disorders Centre and Pulmonary Division, University Hospital Zurich, Raemistrasse 100, Zurich 8091, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Schlatzer
authors.affiliation: Sleep Disorders Centre and Pulmonary Division, University Hospital Zurich, Raemistrasse 100, Zurich 8091, Switzerland.
authors.forename: Esther I
authors.initials: EI
authors.lastname: Schwarz
authors.affiliation: Sleep Disorders Centre and Pulmonary Division, University Hospital Zurich, Raemistrasse 100, Zurich 8091, Switzerland.
authors.forename: Noriane A
authors.initials: NA
authors.lastname: Sievi
authors.affiliation: Sleep Disorders Centre and Pulmonary Division, University Hospital Zurich, Raemistrasse 100, Zurich 8091, Switzerland.
authors.forename: Christian F
authors.initials: CF
authors.lastname: Clarenbach
authors.affiliation: Sleep Disorders Centre and Pulmonary Division, University Hospital Zurich, Raemistrasse 100, Zurich 8091, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gaisl
authors.affiliation: Cardiac Arrhythmia Unit, Cardiovascular Centre, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Laurent M
authors.initials: LM
authors.lastname: Haegeli
authors.affiliation: Cardiac Arrhythmia Unit, Cardiovascular Centre, University Hospital Zurich, Zurich, Switzerland Zurich Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
authors.forename: Firat
authors.initials: F
authors.lastname: Duru
authors.affiliation: Oxford Centre for Respiratory Medicine and NIHR Oxford Biomedical Research Centre, Churchill Hospital, Oxford, UK.
authors.forename: John R
authors.initials: JR
authors.lastname: Stradling
authors.affiliation: Sleep Disorders Centre and Pulmonary Division, University Hospital Zurich, Raemistrasse 100, Zurich 8091, Switzerland Zurich Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland malcolm.kohler@usz.ch.
authors.forename: Malcolm
authors.initials: M
authors.lastname: Kohler
mesh_terms: D001281:Atrial Fibrillation / Q000209:etiology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011312:Pressure; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D012680:Sensitivity and Specificity; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000503:physiopathology*; D013909:Thorax / Q000503:physiopathology*
keywords: Atrial fibrillation; Atrial premature complexes; Intrathoracic pressure changes; Obstructive sleep apnoea; Sudden cardiac death