Substrate-based approaches in ventricular tachycardia ablation.

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Catheter ablation is standard care for ventricular tachycardia (VT) in structural heart disease.
• Mapping and ablating clinical VT can be challenging due to noninducibility, nonsustained rhythm, or hemodynamic intolerance.
• Substrate-based ablation strategies have emerged to address these limitations and improve VT ablation outcomes.

Purpose of the Study:

• To review contemporary substrate-based ablation strategies for ventricular tachycardia (VT).
• To discuss the strengths and weaknesses of different substrate-based approaches.
• To provide an overview of techniques used when direct VT mapping is not feasible.

Main Methods:

• Review of current literature on substrate-based ablation for VT.
• Categorization of strategies into three main approaches: targeting abnormal electrograms, anatomical conduction channels, and areas of slow/decremental conduction.
• Discussion of techniques including "functional" substrate mapping.

Main Results:

• Substrate-based ablation strategies have demonstrated improved outcomes compared to focused ablation of mapped VTs.
• Various approaches exist, including linear ablation lines targeting ventricular scar.
• Three primary categories of substrate ablation are identified and discussed.

Conclusions:

• Substrate-based ablation is a valuable approach for managing ventricular tachycardia (VT) when clinical VT is not amenable to direct mapping.
• Different strategies offer distinct advantages and disadvantages in treating VT associated with structural heart disease.
• Further understanding and refinement of these techniques can optimize patient outcomes.