Peri-Procedural Transmural Electrophysiological (EP) Imaging of Scar-Related Ventricular Tachycardia

Condition(s) studied

Investigational drug(s) / intervention(s)

EP Imaging and Testing: Magnetic Resonance Imaging: pre-procedure imaging is standard care prior to catheter ablation procedures for VT to document anatomy of the heart. 120-Lead Body Surface Mapping: a 120-lead ECG will be recorded using a standardized mapping protocol. 120 disposable radiolucent silver chloride (Ag/AgCl) surface electrodes will be placed on the torso in 18 strips and connected via cables to an advanced acquisition system. Noninvasive programmed stimulation (NIPS) study will be performed using the patient's implanted defibrillator, and is part of standard practice during a VT catheter ablation.

Study summary

Ventricular tachycardia (VT) contributes to over 350,000 sudden deaths each year in the US. Malignant VTs involve an electrical "short circuit" in the heart, formed by narrow channels of surviving tissue inside myocardial scar. An important treatment is to use catheter ablation to "block" the channel that forms the circuit. Effective ablation requires imaging guidance to visualize the VT circuit relative to scar structures in 3D. Unfortunately, with conventional catheter mapping, up to 90% of the VT circuits are too short-lived to be mapped. For the 10% "mappable" VTs, their data are only available during ablation and limited to one ventricular surface. This inadequacy of functional VT data largely limits the knowledge about scar-related VT and ablation strategies, and reduces the ability of clinicians to identify ablation targets and assess ablation outcome.

The central hypothesis of this proposal is that functional VT data, integrated with CT or MRI scar data in 3D, can improve VT ablation efficacy with pre-procedural identification of ablation targets and post-procedural mechanistic elucidation of ablation failure. This research builds on the rapidly increasing clinical interest in electrocardiographic imaging (ECGi), an emerging technique that obtains cardiac electrical activity through inverse reconstructions from ECGs. The specific objective is to push the boundary of ECGi to provide - as a conjunction to intra-procedural catheter mapping - pre-ablation and post-ablation imaging of functional VT circuits integrated with 3D scar structure.

Eligibility

Primary outcome measure(s)

• Termination of Ventricular Tachycardia — Less than 10 minutes post ablation
  The heart rhythm will be monitored continually with ECG electrodes to ascertain whether VT terminates with ablation.
• VT recurrence rate — Less than 6 months post procedure
  Any recurring VT occurring within 6 months post procedure

Trial sites (1)

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