Role of antitachycardia devices in the treatment of ventricular tachyarrhythmias.

Chronic recurrent ventricular tachycardia (VT) can be terminated reproducibly by programmed endocardial right ventricular stimulation. However, antitachycardia pacing is associated with possible acceleration of VT, while frequent occurrence of VT and discomfort of the patient can limit treatment with an automatic implantable cardioverter/defibrillator (AICD; Cardiac Pacemakers Inc.). The combined use of antitachycardia pacing (Tachylog pacemaker; Siemens-Elema) and AICD was therefore evaluated in 6 of 35 patients (aged 50 to 70 years, mean 60.1 +/- 7.7) in whom AICD had been implanted because of VT, which could be terminated by temporary overdrive pacing. With the interactive mode of the Tachylog, termination of VT by the pacemaker as well as by the AICD was assessed after implantation. In the automatic mode, the Tachylog functioned as a bipolar ventricular inhibited (VVI) device with antitachycardia burst stimulation: 2 to 5 stimuli, interval 260 to 300 ms, 1 to 2 interventions. During follow-up of 32 +/- 17 months, the Tachylog terminated VT reliably 50 to 505 times per patient. When burst stimulation accelerated VT, termination was achieved by AICD discharge. Thus, drug-resistant VT can be terminated by antitachycardia pacing avoiding patient discomfort. In case of acceleration, VT can be controlled by the AICD. A universal pacemaker should combine antibradycardia and antitachycardia pacing with backup cardioversion/defibrillation mode.