Characterization of conduction system activation in the postinfarct ventricle using ripple mapping

Area of Science:

• Electrophysiology
• Cardiac Anatomy
• Medical Imaging

Background:

• Three-dimensional (3D) mapping of the ventricular conduction system presents significant challenges.
• Accurate characterization is crucial for understanding cardiac electrical activity, especially post-myocardial infarction.

Purpose of the Study:

• To utilize ripple mapping for distinguishing conduction system activation from adjacent myocardium.
• To characterize the conduction system within the postinfarct left ventricle (LV).

Main Methods:

• High-density mapping (PentaRay, CARTO) was employed during normal rhythm in patients undergoing ventricular tachycardia ablation.
• Ripple maps were analyzed in 1-ms increments to identify Purkinje potentials and tag them on the 3D geometry.
• This process enabled detailed delineation of the ventricular conduction system.

Main Results:

• Purkinje potentials were identified in most patients, particularly at the left posterior fascicle (LPF) and left anterior fascicle (LAF).
• The LAF was significantly shorter and activated for a shorter duration compared to the LPF.
• Patients with left bundle branch block (LBBB) frequently exhibited Purkinje potential-associated breakout, with fewer overall breakouts observed during LBBB.

Conclusions:

• Ripple mapping provides a detailed electroanatomic characterization of the conduction system in the postinfarct LV.
• Broader QRS duration correlated with fewer LV breakout sites from the conduction system.
• A significant majority of LBBB patients demonstrated LV breakout from an intact conduction system.