Usefulness of ambulatory ECG in the diagnosis of sleep-related breathing disorders.

Background: Sleep-related breathing disorders (SRBD) are the additional factor related to poor prognosis in patients with cardiovascular disorders. The apnoea/hypopnoea index (AHI), describing the number of apnoea and hypopnoea episodes per one hour of sleep, has been used as a marker of severity of the disorder. The disease is present in 4% of men and 2% of women above 40 years of age.