[ST segmental changes and arrhythmias in obstructive sleep apnea]

Patients with obstructive sleep apnea show a fall in arterial oxygen saturation during apneas. Whether this is causing myocardial ischemia and consecutively ST segment depressions in the electrocardiogram is not known. Therefore 15 consecutive patients (53 +/- 8 years, apnea index 45 +/- 28, minimal oxygen saturation 71 +/- 14%) with OSA were studied by Holter electrocardiogram and polysomnography. History and exercise testing gave no evidence of coronary heart disease. Three patients had ventricular arrhythmias Lown IVA and 10 had Lown I or III. Three patients showed unspecific negative T waves or ST segment elevations. In no patient significant ST segment depression was found. It is concluded that OSA does not lead to ischemic ST segment depression in the absence of coronary heart disease. The cause of ventricular arrhythmias in OSA seems not be related to myocardial ischemia.