reminds us that we are in the early growth phases of a technology that promises to completely change our approach to the cure of patients with actual or potentially life-threatening ventricular dysrhythmias. It also reminds us that Dr. Mirwoski's dream continues to live and remains as a perpetual challenge to clinicians and engineers alike to bet­ ter perfect and utilize device therapy for our patients. I com­ mend the authors and editors for a superb and timely effort. San Francisco, CA, USA Melvin M. Scheinman, M. D. Preface 1teatment of patients with ventricular tachycardia and pre­ vention of sudden arrhythmic death is one of the most challenging tasks of modem cardiology. 'len years ago anti­ arrhythmic drug therapy was the medical tool used most fre­ quently in the management of patients with life-threatening ventricular tachyarrhythmias.