CLINICAL-SIGNIFICANCE OF VENTRICULAR LATE POTENTIALS IN PATIENTS WITHOBSTRUCTIVE SLEEP-APNEA

Patients with obstructive sleep apnoea (OSA) have an increased cardiov ascular mortality and probably also an increased incidence of sudden c ardiac death. Thus the question arises whether ventricular late potent ials can constitute markers for an increased electric vulnerability in these patients. Signal-averaged electrocardiograms were recorded in 6 4 patients (6 female, 58 male; mean age 53.2 y) with OSA (mean apnoea- hypopnoea index (AHI) 41.7 h(-1) +/- 24.3 h(-1)). Furthermore, a conti nuous ambulatory electrocardiogram and gated radionuclide ventriculogr aphy were performed. Ventricular late potentials were recorded in 5 me n out of 64 patients. Two of them had coronary artery disease (1 patie nt post-myocardial infarction), 2 hypertension, and 1 nocturnal hypert ension. No correlation could be traced between left ventricular ejecti on fraction, severity and extent of ventricular premature beats, or se verity of OSA and occurrence of ventricular late potentials. It was no ticeable, however, that the patients with ventricular late potentials had severe OSA (mean AHI 50.2/h vs. 40.9/h). Although OSA may lead to structural myocardial changes that could be the basis for re-entrant c ircuits, ventricular late potentials were found in only 7.8% of these patients. The results of this study demonstrate that at present ventri cular late potentials and signal-averaged electrocardiograms do not pr ove useful as screening methods for risk stratification of patients wi th OSA.