Transmural Electrophysiologic and Scar Imaging on Porcine Heart with Chronic Infarction

Abstract

Myocardial scar is the most common substrate for malignant arrhythmia and cardiac arrest. Radiofrequency ablation, as one of the emerging mainstream therapies, is subject to limited success rate because of the inadequate assessment of scar substrates that currently relies on electrophysiologic (EP) map acquired on endocardial and occasionally epicardial surfaces. As myocardial scar is often complex with shapes varying with the depth of the myocardium, endocardial and epicardial maps may differ substantially, and may fail to identify mid-wall fibrosis that exist in ~30% of patients with nonischemic cardiomyopathy. Alternatively, noninvasive and transmural scar delineation by current imaging techniques does not always show electrically altered functional substrates. Participating in CESC’11, we presented a new application of the previously developed method of transmural EP imaging, where epicardial unipolar electrograms acquired by CARTO together with MRI-derived ventricular anatomical data of a porcine heart with chronicle myocardial infarction were used for computing the transmural EP dynamics and subsequently classifying conduction blocks of the porcine heart. Validation was performed versus CARTO electroanatomic maps on the epicardium and endocardium, as well as DW-MRI enhanced anatomical scars. This allowed detailed examinations of the reported method in computing transmural EP anomalies using only surface data and without any condition-specific knowledge a priori, which could not be achieved with either current EP mapping or medical imaging techniques alone.