Ventricular Tachycardia Ablation: Past, Present, and Future Perspectives

Although implantable cardioverter-defibrillators positively affect survival in patients at increased risk for arrhythmic sudden cardiac death, quality of life can be negatively affected by recurrent therapies. Ventricular tachycardia (VT) ablation targets clinical arrhythmias to prevent recurrence. Although treatment of VT initially required open heart surgery, it has since been replaced by percutaneous ablation, a safe and effective catheter-based therapy to ablate myocardium from either the endocardial or the epicardial surface. Four basic mapping techniques are used to guide VT ablation: activation, entrainment, and pace and substrate mapping. Current recommendations for VT ablation, especially in the setting of structural heart disease, mostly reserve this treatment for patients for whom antiarrhythmic therapy has failed or is not tolerated or desired. These recommendations derive from multiple observational reports and several randomized prospective studies in patients with VT in the setting of ischemic cardiac disease. Patients are usually referred late in their clinical course for VT ablation, limiting enrollment in clinical trials and resulting in limited prospective randomized data on long-term outcomes with ablative therapy. Future research efforts should address unmet needs, including more rigorous assessment of survival benefit from VT ablation, outcomes data of VT ablation in patients with nonischemic cardiomyopathy, and assessment of strategies to improve intramural substrate ablation. Emerging technologies with disruptive potential include the use of lower ionic strength irrigants, energy delivery guided by impedance modulation, simultaneous unipolar and bipolar ablation, and novel ablation catheters, including the retractable needle-tip electrode catheter. Promising alternatives to radiofrequency ablation include alcohol ablation from the coronary arterial or venous system, direct current or pulsed field electroporation, and stereotactic body radiotherapy guided by noninvasive substrate mapping. Future studies are needed to demonstrate the safety and efficacy of these novel technologies compared with standard radiofrequency catheter ablation.