The value of functional substrate mapping in ventricular tachycardia ablation

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Ventricular tachycardia (VT) in structural heart disease often involves re-entrant mechanisms.
• Current gold-standard mapping techniques (activation and entrainment) are limited by hemodynamic intolerance, noninducibility, or nonsustained VT.
• High recurrence rates after VT ablation necessitate improved substrate characterization methods.

Purpose of the Study:

• To review advances in substrate mapping for identifying VT circuits in structural heart disease.
• To highlight the role of multielectrode mapping and substrate-guided approaches in scar-related VT.
• To discuss the benefits of incorporating ventricular extrastimulation into substrate mapping strategies.

Main Methods:

• Review of current literature on VT mapping techniques, focusing on substrate mapping during sinus rhythm.
• Discussion of substrate-guided approaches like scar homogenization and late potential mapping.
• Exploration of mapping strategies incorporating ventricular extrastimulation and automated annotation.

Main Results:

• Multielectrode mapping of abnormal electrograms enhances the identification of scar-related VT mechanisms.
• Substrate mapping during sinus rhythm overcomes limitations of tachycardia-based mapping.
• Ventricular extrastimulus mapping increases substrate mapping accuracy, identifying dynamic substrate changes like local abnormal ventricular activities.

Conclusions:

• Substrate mapping techniques, particularly those incorporating ventricular extrastimulation, are crucial for accurate VT circuit identification.
• These advanced methods can lead to less extensive ablation and more accessible VT ablation procedures.
• Improved mapping strategies promise to reduce VT recurrence rates in patients with structural heart disease.