The role of implantable pacemakers in the therapy of tachycardias.

Antitachycardia electrical stimulation involves significant problems of sensing the cardiac rhythm and determining whether a tachycardia exists. The simple algorithms developed for bradycardia pacing are inadequate for tachycardia pacing. Electrogram signal analysis and cardiac activation analysis with at least two leads will be required to make a device diagnosis of a tachycardia. Termination of a tachycardia reliably and consistently is difficult and has only been accomplished uniformly by defibrillation. Further development of devices which are multimodal in termination capability is necessary. A registry for tachycardias and for tachycardia management is required to provide concentrated and analyzable data from a modality as yet infrequently used.