Noninvasive Visualization of the Atrioventricular Conduction System Using Cardiac Computed Tomography

Area of Science:

• Cardiovascular Imaging
• Cardiac Electrophysiology
• Medical Physics

Background:

• Noninvasive localization of the atrioventricular conduction system (AVCS) is crucial for planning complex cardiac surgeries and interventions.
• Accurate anatomical mapping enhances procedural safety and efficacy, particularly in transcatheter aortic valve replacement and congenital heart disease surgeries.

Purpose of the Study:

• To evaluate the accuracy of preprocedure contrast-enhanced cardiac computed tomography (CECT) in localizing the AVCS.
• To test if CECT can identify the insulating fat surrounding the AVCS for precise anatomical localization.

Main Methods:

• Prospective cohort study at an academic tertiary care center.
• Inclusion of patients undergoing atrial fibrillation ablation with preprocedure CECT and electroanatomic mapping (EAM).
• Measurement of the distance between the His electrogram signal and the AVCS fat segmentation on registered CECT and EAM images.

Main Results:

• The study included 20 patients (mean age 66 years, 75% male).
• The mean attenuation of AVCS fat segmentation on CECT was 2.9 Hounsfield units.
• The mean distance from the His electrogram to the closest AVCS fat voxel was 3.3 mm.

Conclusions:

• CECT can accurately localize the fatty tissue insulating the AVCS.
• This noninvasive technique may improve the efficacy and safety of procedures targeting the cardiac conduction system.
• CECT offers a valuable tool for preprocedural planning in cardiac interventions involving the AVCS.