Hybrid Therapies for Ventricular Arrhythmias

In recent years several trials demonstrated the efficacy of implantable cardioverter-defibrillation (ICD) therapy in reducing cardiac and total mortality in patients affected by rapid ventricular tachycardia (VT) and/or ventricular fibrillation. Nevertheless, ICD do not prevent arrhythmia recurrences, thus being a palliative and not a curative treatment modality. The tolerance to ICD therapy varies greatly, and within individuals, this leading to a nonuniform acceptance of this form of therapy. The very frequent occurrence of VT, defined as an arrhythmic storm, may be a life threatening condition. The majority of ICD patients is under antiarrhythmic drug therapy, to reduce episodes of VT or to make antitachycardia pacing more effective by slowing the tachycardia rate. Drug therapy, however, may cause additional problems, and does not represent the optimal solution. The prevention of VT and/or ventricular fibrillation episodes and excessive ICD therapy, remains a worthwhile goal. Radiofrequency catheter ablation (RFCA) is a curative approach, and can be expected to reduce the frequency of recurrent VT episodes in the majority of patients. The combination of these treatment modalities (ICD and RFCA) is often described as hybrid therapy, implying that the two treatments act providing some form of synergism. In experienced centers, RFCA is now performed, regardless of whether the VT rate is rapid and/or is hemodynamically unstable. Newer mapping and ablation techniques are now available, enhancing the acute success rate of the procedure. In this review the most recent application of VT catheter ablation and the use of advanced mapping and ablation techniques will be discussed.