Discordance in Scar Detection Between Electroanatomical Mapping and Cardiac MRI in an Infarct Swine Model.

Area of Science:

• Cardiovascular imaging
• Electrophysiology
• Myocardial scar assessment

Background:

• Low voltage electrograms on electroanatomical mapping (EAM) correlate with myocardial scar.
• Voltage amplitude is affected by scar proximity and extent.
• Late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) provides a reference standard for myocardial scar.

Purpose of the Study:

• To evaluate the sensitivity of EAM in detecting myocardial scar.
• To compare EAM findings with LGE-derived scar characteristics from CMR.
• To assess the reliability of low voltage EAM as a surrogate for myocardial scar.

Main Methods:

• Twelve swine underwent induced myocardial infarction (anterior or inferior wall).
• Animals underwent both CMR and EAM using a multielectrode catheter.
• CMR-derived scar (LGE) and EAM voltage maps were analyzed for concordance.

Main Results:

• LGE volume was similar between anterior and inferior infarction groups.
• Anterior wall scars (LAD) were subendocardial with significant thinning.
• Inferior wall scars (LCx) extended transmurally with minimal thinning; low voltage areas on EAM corresponded to scar in anterior but not inferior walls.

Conclusions:

• EAM's ability to detect scar is limited in thicker myocardial regions.
• Discordance between LGE and EAM suggests limitations of current EAM systems for scar identification in transmural scar.
• Myocardial wall thickness influences the accuracy of EAM scar detection.