Catheter ablation. Present role and projected impact on health care for patients with cardiac arrhythmias.

T en years ago, the only available treatment modality for patients with drug-refractory supraventricular tachycardia was surgery. Surgical techniques included direct dissection or cryodesiccation of the His bundle for tachycardia control.1'2 During the past decade, catheter techniques have been introduced that replicate the surgical experience without the expense and morbidity associated with cardiac surgery. The first decade of catheter ablative therapy was directed primarily at disruption of the atrioventricular (AV) junction and, like the surgical approach, entailed the need for life-long cardiac pacing. In essence, this procedure served as a palliative procedure in that intractable supraventricular tachycardia was replaced by the need for permanent cardiac pacing. During the past 2 years, more specific ablative procedures have been introduced for patients with AV nodal reentry and for those with accessory bypass tracts in all locations. The latter procedures hold great promise for providing definitive cure for these patients. It should be emphasized that current catheter ablative procedures represent a direct outgrowth of impressive advances in our understanding of arrhythmia mechanism as well as in the ability to precisely define the anatomic components of the tachycardia circuits in patients with supraventricular tachycardia. The pioneer efforts of our surgical colleagues often served as the creative spark for development of newer catheter procedures. However, impressive gaps remain in both our understanding of basic mechanisms and our ability to locate critical components of the tachycardia circuit for patients with ventricular tachycardia. hence, application of catheter ablative techniques to patients with ventricular tachycardia remains an important frontier for clinical electrophysiologists.