[Screening for sleep apnea in cardiovascular patients in clinical routine]

Sleep apnea syndromes (SAS) are highly prevalent in cardiovascular patients. Because diagnostics are cost and labor intensive, these patients often remain undiagnosed. For this reason, simple screening methods for SAS in daily clinical practice are very important. Standardized questionnaires are one way to screen patients, i.e., simple standardized questionnaires have been shown to be highly predictive in OSA, but not in CSA patients. Simple ambulatory screening devices use oxymetry and/or nasal flow to determine the apnea-hypopnea index (AHI). These devices have been shown to be highly effective in screening for OSA and CSA. In addition, algorithms that calculate the electrocardiography (ECG)-derived AHI using heart rate variability and/or QRS morphology from Holter ECG recordings are also promising. Especially the latter method could become a simple tool for cardiologists to screen for SAS in clinical routine.