There are several pathophysiological mechanisms by which both obstructive and central sleep apnea may increase risk of sudden cardiac arrhythmic death in ICM patients. Considering the high prevalence of sleep disordered breathing in patients with ICM, sleep apnea represents a modifiable risk factor, where proper treatment may decrease risk of sudden cardiac death and/or improve cardiovascular outcomes in ICM patients. However, randomized studies specifically addressing the role of sleep apnea in risk of sudden cardiac arrhythmic death in ICM patients are needed to clarify the existing controversy and provide information highly needed for routine clinical practice.