Ventricular tachycardia ablation

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sara Zand, M.D.[2] Rim Halaby, M.D. [3]

Catheter ablation is useful for treating ventricular arrhythmia when drugs are ineffective. Monomorphic VT is a suitable target for ablation. Ablation can be used for polymorphic VT or VF if an initiating PVC focus or substrate is accessible.

• Catheter ablation is useful for treating ventricular arrhythmia when drugs are ineffective.
• Monomorphic VT is a suitable target for ablation.
• Ablation can be used for polymorphic VT or VF if an initiating PVC focus or substrate is accessible.
• Mechanism and location of ventricular arrhythmia may determine The ablation strategy, risks and outcomes.
• The location of ventricular arrhythmia maybe subendocardium or subepicardium.
• Approach for ablation of ventricular arrhythmia originated subendocardium can be done through a transvenous for the right ventricle or transaortic/transeptal of the left ventricle.
• percutaneous subxiphoid puncture is used for pericardial access.
• Programmed electrical stimulation by catheter is attempted for induction of ventricular arrhythmia and ablation.
• In some cardiomyopathies the location of ventricular arrhythmia in the myocardium is inaccessible or in idiopathic ventricular arrhythmia induction of ventricular arrhythmia for mapping is difficult.

• Ideopathic ventricular arrhythmia appears in structurally normal heart or without genetic predisposition disorders.
• Monomorphic ventricular arrhythmia is the Most common idiopathic ventricular arrhythmia
• The underlying mechanism of ventricular arrhythmia is triggered activity or abnormal automaticity, or rarely reentry.
• Catheter ablation is a choice approach for symptomatic patients or when antiarrhythmic medications is ineffective or not tolerated.
• The aim of the approach is finding the earliest site of ventricular activation or ventricular pacing for inaccessible sites.

• The most common ventricular arrhythmia in structurally heart disease is sustained monomorphic reentry ventricular tachycardia related to scar formation.
• The site of reentry substrate for VT in myocardial infarction is sunendocardium.
• For non-ischemic cardiomyopathy the substrate of reentry VT is in variable sites including epicardial surface of both ventricles, or midmyocardium where is difficul to approach.
• Area of ablation involves low electrogram voltage.
• Based on electrocardiographic and pacing characteristics during sinus rhythm, the reentry circuit substrate is approached for ablation.^[1]

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