Diagnostic value of a pacemaker high rate episode counter when programmingthe ventricular tachycardia zone of an ICD

A 72-year-old man with an ICD and a pacemaker was presented with an episode of sustained VT that accelerated to VF. The ICD failed to detect the event and deliver therapy, despite a VT apparently within the VT detection zone. The ICD detected the event after degeneration to VF and delivered appropri ate therapy. The high rate event feature of the pacemaker was useful in det ermining proper function of the ICD along with optimal programming of VT de tection.