Catheter ablation of ventricular fibrillation triggers and electrical storm

Abstract

Ventricular fibrillation (VF) and electrical storm remain challenging conditions to manage despite the availability of various treatment modalities. Insertion of an implantable cardioverter defibrillator (ICD) remains the gold standard method for lowering the risk of sudden cardiac death in patients deemed to be at greatest risk of ventricular arrhythmias. However, ICDs do not alter the underlying substrate responsible for the arrhythmic events and a significant proportion of patients with ICDs may experience VF storm which may be life threatening and difficult to control with medication. Catheter ablation (CA) of the triggers or abnormal electrical substrate responsible for VF storm is an important treatment option in rare cases. In this article, we present an overview of the current theories underlying the mechanisms of VF and discuss how the technique of CA may be used to treat the triggers of VF and electrical storm. We review the literature on outcomes in patients who have undergone CA for VF in a variety of different settings, including those with structural heart disease and structurally normal hearts (e.g. patients with inherited arrhythmogenic diseases and idiopathic VF) and discuss the future directions in this field.

Acute and long term outcomes of catheter ablation using remote magnetic navigation for the treatment of electrical storm in patients with severe ischemic heart failure

“…To date, ES remains a challenging condition to manage despite the availability of various management techniques [18]. Most arrhythmic episodes (86-97%) during ES consist of scar-related monomorphic VT [2,19], which makes it feasible for catheter ablation to control ES.…”

Second coupling interval of nonsustained ventricular tachycardia to distinguish malignant from benign outflow tract ventricular tachycardias

“…21,22 Functional block or delayed conduction by rapid firing due to triggered activity, or microreentry arising from a single focus, can lead to chaotic ventricular refractoriness (producing dispersion of refractoriness 23 ) without an organic delayed conduction zone. 24 With up-regulation of the beta-adrenergic receptor system, excessive release of sarcoplasmic reticulum Ca 2þ by phosphorylation of RyR2 and disorganizing ventricular refractoriness initiate polymorphic rapid VT and VF. 25 Second, in our present study, more than 1 focus of VT was identified in the malignant VT group during RFCA sessions.…”

Syncope in a young man: Role of Purkinje fibres in idiopathic ventricular fibrillation

“…Several groups have reported successful ablation of Purkinje-related VF post myocardial infarction, as well as in amyloidosis, chronic myocarditis and non-ischemic cardiomyopathy. Unlike cases of structural heart disease in which there is a clear substrate, the role of ablation in idiopathic VF, in which the underlying abnormality may be a genetic condition with more widespread electrical instability, remains undefined [6]. Recurrence rates are reported at around 18% at 2 years [7] and therefore ablation cannot be thought as a cure or substitute for an ICD, although it plays a useful role in controlling electrical storm.…”