The relationship between sleep disorders and heart failure is complex and incompletely understood. It is known that 60% of heart failure patients have some form of sleep disordered breathing. Within this population of patients with both HF and sleep dosorders one finds a higher rate of atrial fibrillation, ventricular arrythmia, progressive symptoms, and lower ejection fraction. Importantly, there is also a higher mortality associated with the presence of sleep disorder in heart failure patients.