Evaluation of Atrial Electromechanical Delay in Simulated Obstructive Apnea in Healthy Individuals

Objective: Studies have suggested that obstructive sleep apnea portends an increased risk of dysrhythmia, such as atrial fibrillation. The time interval between the onset of atrial electrical activity and the onset of atrial contraction has been defined as atrial electromechanical delay, and prolonged atrial electromechanical delay has been proposed as a predictor of atrial fibrillation. The aim of this study is to simulate obstructive sleep apnea through respiratory maneuvers to evaluate its acute effects on atrial electromechanical delay.Material and Methods: A total of 50 healthy individuals were included in the study and tissue Doppler images were recorded during simulated obstructive apnea (Mueller maneuver, voluntary end-expiratory central apnea and normal breathing. From these recordings intra-atrial and interatrial electromechanical delay were measured.Results: Interatrial electromechanical delay (+10.1ms during Mueller maneuver; +8.7ms during voluntary end-expiratory central apnea; p<0.001) and left intra-atrial electromechanical delay (+7.3 ms during Mueller maneuver; +6.7ms during voluntary end-expiratory central apnea; p<0.001) increased during Mueller maneuver and voluntary end-expiratory central apnea compared to normal breathing in all healthy subjects.Conclusion: Simulated obstructive sleep apnea increased intra-atrial and interatrial electromechanical delay in healthy subjects. These findings may indicate that acute intrathoracic pressure change in obstructive sleep apnea may be an independent trigger of atrial fibrillation.