A Pre-clinical Framework to Characterize Peri-infarct Remodelling Using in vivo T1 Maps and CARTO Data

The purpose of this work was to use

in vivo

MR imaging and electro-anatomical maps to characterize dense scars and border zone, BZ (a mixture of collagen and viable fibers). To better understand how these measures might probe potentially arrhythmogenic substrates, we developed a preclinical swine model of chronic infarction and integrated

in vivo

MRI and electrophysiology (EP) data in five swine at 5-6 weeks post-infarction. Specifically, we first aligned and registered T

1

-maps (from MR studies) and bipolar voltage maps (from CARTO-EP studies) using Vurtigo, an open source software. We then performed a quantitative analysis based on circumferential segments defined in the short-axis of MR images. Our results demonstrated a negative linear relation between bipolar voltage maps and T

1

maps within the first two mm of the endocardial surface. The results of our novel approach suggest that T

1

-maps combined with limited EP measurements can be used to evaluate the biophysical properties of healing myocardium post-infarction, and to distinguish between the infarct categories (i.e., dense scar vs. BZ) with remodelled electrical characteristics.