Cardiac pacing and pacemakers II. Serial electrophysiologic-pharmacologic testing for control of recurrent tachyarrhythmias.

The place of pacemakers in the treatment of tachyarrhythmias has expanded far beyond the initial role in the brady-tachy syndrome, of providing a "minimum guaranteed rate" while medications suppress the tachycardia. Techniques have been developed for prevention, termination, and duplication of a patient's spontaneous tachycardia under safe catheterization laboratory conditions. Combined with accumulating information about the normal responses to electrophysiologic stresses, these techniques have led to a new dimension in arrhythmia control. Most tachycardias previously felt to be refractory can be controlled after serial electrophysiologic-pharmacologic testing, during which sequential pharmacologic and pacer regimens are tested until a combination is found which prevents induction of tachycardias, and/or a pace mode is found which reliably terminates the tachycardia. Use of such an approach reduces hospital admissions and referral for surgery, and eliminates prolonged hospitalization for assessment of therapy in patients with infrequent but potentially lethal spontaneous tachycardias.