Obstructive sleep apnoea / hypopnoea syndrome is a disease of multisystemic involvement, with particular repercussions on the cardiovascular system, and thus a high impact on morbidity and mortality. Several pathophysiological mechanisms have been demonstrated that explain and suggest a direct and proportional relationship to the damaged caused by the condition, especially for tachyarrhythmias, specifically for atrial fibrillation, and also for bradyarrhythmias, with a demonstrated improvement with continuous positive airway pressure. As the association with atrial flutter and ventricular arrhythmias has shown contradictory results in some studies, the relationship is still not clear.