PT - JOURNAL ARTICLE AU - Tsogyal D. Latshang AU - Yvonne Nussbaumer-Ochsner AU - Barbara Kaufmann AU - Silvia Ulrich-Somaini AU - Malcolm Kohler AU - Robert Thurnheer AU - Ivan Fauchère AU - Ardan M. Saguner AU - Frank Scherff AU - Firat Duru AU - Konrad E. Bloch TI - Acetazolamide improves cardiac dysrhythmias in patients with obstructive sleep apnea at altitude. A randomized controlled trial DP - 2012 Sep 01 TA - European Respiratory Journal PG - 3291 VI - 40 IP - Suppl 56 4099 - http://erj.ersjournals.com/content/40/Suppl_56/3291.short 4100 - http://erj.ersjournals.com/content/40/Suppl_56/3291.full SO - Eur Respir J2012 Sep 01; 40 AB - Background: Untreated lowlanders with obstructive sleep apnea syndrome (OSA) benefit from acetazolamide (AC) during an altitude stay in terms of improved nocturnal oxygenation, breathing disturbances and sleep quality (Nussbaumer-Ochsner, Chest 2012). The current study evaluates whether AC reduces the increased rate of cardiac dysrhythmias at altitude.Methods: 43 OSA patients living at <600m discontinued CPAP 3 days before baseline examination at 490m and during 2 altitude sojourns at 1860-2590m for 3 days each, one on AC 2x250mg/d, the other on placebo, according to a randomized cross-over design. Holter ECG and polysomnography were performed at 490m and at altitude.Results: At altitude on placebo, heart rate was higher and dysrhythmias were more prevalent than at 490m. AC reduced bradycardia events, apneas/hypopneas and improved oxygen saturation [table].Conclusions: The increased heart rate and the higher prevalence of dysrhythmias at altitude are consistent with increased sympathetic tone associated with hypoxemia. AC reduces bradycardia events at altitude, possibly by improving sleep disordered breathing.View this table:Dysrhythmias, oxygen saturation and breathing disturbancesGrants: Swiss National Science Foundation; Lung League of Zurich; Clinical Trials Center, University Hospital of Zurich, Switzerland.