The proposed pilot study is designed as a prospective observational cohort study to investigate the QT interval before, during and after general anesthesia. It aims to determine the incidence of perioperative QT prolongations. A customary long term EKG recording device will be connected to a random sample of patients undergoing general anesthesia. Using these continuous EKG tracings, the lengths of the QT interval will be analyzed during the perioperative period.