Circadian Variation of Sustained Ventricular Tachycardia in Patients With Coronary Artery Disease and

Background While previous studies using epidemiological data and ambulatory ECG monitoring have shown peak occurrence of sudden death and nonsustained ventricular tachycardia in the morning, none have examined circadian variation of potentially life-threatening ventricular tachycardia (VT), nor has any study observed circadian behavior of any arrhythmias in individuals followed longitudinally. We used the event memory of multiprogrammable implantable cardio-verter-defibrillators to evaluate the circadian pattern of sus-tained VT over time. Methods and Results Data were reviewed from 32 consecu-tive patients with coronary artery disease and sustained VT who had received the Ventak PRX (CPI, Inc) cardioverter-defibrillator between May 1991 and August 1993 and had experienced at least one episode of VT terminated by thei