Obstructive sleep apnea and central sleep apnea with Cheyne-Stokes respiration are associated with an increased risk of cardiac arrhythmia. Apnea- associated arrhythmia may contribute to sudden cardiac death and premature mortality in those patients. Both forms of sleep apnea excert strong modulatory effects on the autonomic system with a special autonomic profile. Profound vagal activity is leading to bradyarrhythmias, and sypathico-excitation to tachyarrhythmias. Atrial fibrillation and ventricular arrhythmias in obstructive and central sleep apnea patients are mainly found in combination with cardiovascular comorbidity (coronary heart disease, hypertensive heart disease, chronic heart failure). Bradyarrhythmias in OSA are induced by a cardioinhibitory vagal reflex due to obstructed airway. CPAP-therapy has been demonstrated to reduce arrhythmias.