Peripheral arterial tonometry for the diagnosis of obstructive sleep apnea.

Sleep related breathing disorders have been recognized as a risk factor for cardiovascular disorders. Peripheral arterial tonometry (PAT) allows to monitor vasoconstriction on the finger continuously and non-invasively. We investigated whether the rapid changes of autonomous function can be assessed by PAT. In 21 patients with obstructive sleep apnea and arterial hypertension we recorded PAT in parallel to cardiorespiratory polysomnography and invasive arterial blood pressure. The correlation between periodic PAT attenuations and the total number of apneas (r = 0.656, p < 0.01) and the total number of cortical arousal (r = 0.583, p < 0.01) were significant. The PAT signal cannot substitute blood pressure but allows a good recognition of apneas and subcortical arousal and gives additional information on changes of sympathetic and parasympathetic tone during sleep.