Delayed repolarization syndrome.

The electrocardiograms of 18 patients with atypical ventricular tachycardia manifested as torsade de pointes, ventricular fibrillo-flutter, polymorphous ventricular tachycardia, and uniform ventricular tachycardia were analyzed. The patients were divided into two groups: The first group included 10 patients with prolonged Q-T intervals or abnormal U waves (delayed repolarization) and the second group included eight patients with normal ventricular repolarization. All of the electrocardiographic manifestations of atypical ventricular tachycardia were seen in both groups, regardless of the duration of the Q-T interval or the presence of an abnormal U wave. It is suggested that QRS morphology during the tachycardia is not sufficient to distinguish between delayed repolarization and other causes of atypical ventricular tachycardia. Finally, because the electrocardiogram may vary among different patients and from one episode to the next in a single patient due to abnormal repolarization, it is recommended that the term delayed repolarization syndrome be used to identify the arrhythmia.