Catheter-based Ablation for Ventricular Arrhythmias

Abstract

Catheter ablation for patients with recurrent ventricular arrhythmias has emerged as an important and effective treatment option. The approach to ablation, and the risks and likely efficacy are determined by the nature of the severity and type of underlying heart disease. Although implantable defibrillators remain the corner stone for prevention of sudden cardiac death, ablation successfully reduces tachycardia recurrences and storms of ventricular arrhythmias triggering defibrillator shocks in patients with structural heart disease. Our understanding of idiopathic ventricular tachycardia (VT) has grown substantially with several new sites of VT origin recognized in recent years. Ablation is often curative for idiopathic VT. This review discusses common mechanisms and clues to diagnosis of the various VTs, and current advances in ablation options. In particular, endocardial ablation techniques have been complemented by newer approaches such as percutaneous epicardial ablation. In rare cases, transcoronary alcohol ablation can be effective for life-threatening arrhythmia.

Nonlinear and stochastic dynamics in the heart

“…There is no doubt that the mechanistic insights gained from the nonlinear dynamics and mathematical modeling will be of great importance for prediction of arrhythmia risk and finding proper therapeutic targets, not only for drug therapies but also for device therapies, such as ICD and catheter ablation. Similar to defibrillation, catheter ablation is another widely used therapy for treating arrhythmias [575, 576], which is largely based on anatomical reentrant circuit in tissue and has limited efficacy. Future mathematical and computational studies are needed to gain better mechanistic insights and to improve the efficacy of these device therapies.…”

Relation of the Unipolar Low‐Voltage Penumbra Surrounding the Endocardial Low‐Voltage Scar to Ventricular Tachycardia Circuit Sites and Ablation Outcomes in Ischemic Cardiomyopathy

“…6 Monomorphic VT was induced with programmed ventricular stimulation. Endocardial voltage mapping of the left ventricle (LV) for acquisition of endocardial bipolar and unipolar voltages was performed in sinus or paced rhythm either by retrograde aortic or transseptal approach.…”

“…Targeting VT isthmuses in the endocardial LVA is an effective technique to ablate most VTs in ischemic cardiomyopathy. 6 However, the extent to which failure of ablation is related to greater depth of VT circuits in the inhomogeneous intramural regions of infarct scar as judged by endocardial unipolar voltage mapping is not known.…”

Management of electrical storm: The mechanism matters

“…Activation mapping is useful when seeking the VT origin during an electrical storm. The earliest activation at successful ablation sites typically precedes the surface QRS onset by 20–40 ms, with unipolar electrograms exhibiting a QS pattern with a rapid initial downstroke [22].…”