VENTRICULAR-TACHYCARDIA - PATHOPHYSIOLOGY AND RADIOFREQUENCY CATHETERABLATION

Limitations of pharmacological therapy for VT have led to great intere st in alternative nonpharmacological therapies. The appeal of a curati ve therapy for VT initially led to the search for operative techniques to identify and destroy the underlying substrate, and more recently, has resulted in the development of catheter techniques to achieve the same goal in the electrophysiology laboratory. Investigations into the pathophysiology of VT have resulted in the recognition that this arrh ythmia reflects a mechanistically and anatomically heterogeneous set o f disorders. Recent growth in our understanding of these distinctions has both led to, and resulted from, simultaneous advances in catheter ablation techniques. The clinical electrophysiology laboratory has ser ried as a testing ground for theories derived from in vitro and animal experiments while also providing its own set of human experimental da ta regarding the pathophysiology and treatment of VT. As a result of t his process, several distinct forms of VT that are amenable to cathete r ablation have been characterized. This article will summarize curren t knowledge of the pathophysiology of various VT subtypes and of techn iques for catheter mapping and ablation.