[Analysis of long-term blood pressure measurements during sleep]

Fifty patients with sleep-related breathing disorders and arterial hypertension underwent diagnostic polysomnography for two nights; EEG, EOG, EMG, and respiratory signals were recorded in parallel with invasive blood pressure. Computerized evaluation was performed to calculate systolic and diastolic blood pressure values, as well as heart rate beat-to-beat. All signals were stored once per second for further evaluation. These time series were analyzed in respect of underlying periodicities by means of spectral analysis. It was possible to distinguish four different groups of patients according to the compressed spectral arrays. Pronounced peaks of different extents were found that reflected both periodicities of respiration (3-5 s) and periodicities of sleep apnea (30-60 s). A comparison of spectral analysis of blood pressure and heart rate showed that systolic blood pressure is suited best to recognize periodicities related to respiration and apneas.