Combined ventricular endocardial and epicardial substrate mapping using a sonomicrometry-based electroanatomical...

Area of Science:

• Cardiovascular Electrophysiology
• Medical Imaging
• Cardiac Ablation Technologies

Background:

• Magnetic electroanatomical mapping systems (MEAM) accurately delineate myocardial scar.
• Assessing the efficacy of sonomicrometry-based electroanatomic mapping (SEAM) for substrate mapping is crucial.

Purpose of the Study:

• To evaluate the capability of SEAM to create endocardial and epicardial substrate maps of infarcted ventricular myocardium.
• To compare SEAM's accuracy against MEAM and gross pathology.

Main Methods:

• Created combined epicardial and endocardial left ventricular (LV) substrate maps in 7 swine using SEAM and MEAM.
• Identified scarred myocardium by bipolar electrogram amplitude < 1.5 mV.
• Guided radiofrequency ablation to scar borders defined by SEAM.

Main Results:

• LV endocardial chamber volume by SEAM correlated well with MEAM (r=0.77, p < 0.05).
• SEAM-determined infarcted tissue area highly correlated with gross pathology (endocardial r=0.96, epicardial r=0.92, p < 0.05).
• SEAM scar area correlated well with MEAM scar area (endocardial r=0.91, epicardial r=0.90, p < 0.05).

Conclusions:

• SEAM accurately reconstructs 3D voltage maps of ventricular endocardial and epicardial surfaces.
• SEAM effectively guides radiofrequency ablation lesions to the scar border zone.