This third module in the series reviews the indications and contraindications for use of ASV therapy in patients with central sleep apnea, variable breathing patterns such as seen in Cheyne-Stokes respiration, or treatment emergent complex sleep apnea in OSA patients. This module includes a comprehensive overview of what ASV is, how it works, which patients benefit from ASV therapy, and the potential risks. The module concludes by addressing the pathophysiology of the disorders that require this type of therapy, principles of operation, and the titration protocol itself, thereby ensuring a thorough understanding of the appropriate use of this therapy.