Catheter ablation of monomorphic ventricular tachycardia.

PURPOSE OF REVIEW

Patients with ventricular tachycardia are subject to frequent recurrences and antiarrhythmic drug therapy has been disappointing. Catheter ablation offers an alternative means of controlling ventricular tachycardia.

RECENT FINDINGS

The origin and pathophysiology of ventricular tachycardia are being defined for newly recognized types of ventricular tachycardia as well as scar-related ventricular tachycardias. The approach to mapping and ablation of ventricular tachycardia depends on the nature of the arrhythmia substrate, which is largely determined by the underlying heart disease. Focal origin ventricular tachycardias often occur in patients without structural heart disease. The right ventricular and left ventricular outflow tracts are common locations. Ablation is usually successful unless the focus is epicardial in location or in close proximity to the ostia of a coronary artery. The reentry path for idiopathic left ventricular reentrant ventricular tachycardia is now defined. In patients with heart disease, most ventricular tachycardias are scar related, with areas of fibrous tissue forming the border for reentry paths. Substrate mapping defines areas of scar, abnormal conduction, and reentry circuit exits during sinus rhythm. Ablation of multiple ventricular tachycardias and unstable ventricular tachycardias performed largely during sinus rhythm is often possible. Ablation is usually adjunctive therapy to an ICD in these patients. Epicardial mapping and ablation are needed in some patients.

SUMMARY

Ablation is a reasonable alternative to antiarrhythmic drug therapy for controlling frequent ventricular tachycardia episodes in many patients. Further technological advances can be anticipated.