Tissue-Specific Optical Mapping Models of Swine Atria Informed by Optical Coherence Tomography

Abstract

Computational models and experimental optical mapping of cardiac electrophysiology serve as powerful tools to investigate the underlying mechanisms of arrhythmias. Modeling can also aid the interpretation of optical mapping signals, which may have different characteristics with respect to the underlying electrophysiological signals they represent. However, despite the prevalence of atrial arrhythmias such as atrial fibrillation, models of optical electrical mapping incorporating realistic structure of the atria are lacking. Therefore, we developed image-based models of atrial tissue using structural information extracted from optical coherence tomography (OCT), which can provide volumetric tissue characteristics in high resolution. OCT volumetric data of four swine atrial tissue samples were used to develop models incorporating tissue geometry, tissue-specific myofiber orientation, and ablation lesion regions. We demonstrated the use of these models through electrophysiology and photon scattering simulations. Changes in transmural electrical conduction were observed with the inclusion of OCT-derived, depth-resolved fiber orientation. Additionally, the amplitude of optical mapping signals were not found to correspond with lesion transmurality because of lesion geometry and electrical propagation occurring beyond excitation light penetration. This work established a framework for the development of tissue-specific models of atrial tissue derived from OCT imaging data, which can be useful in future investigations of electrophysiology and optical mapping signals with respect to realistic atrial tissue structure.

Mapping the human pulmonary venoatrial junction with optical coherence tomography

“…OCT imaging of the PVs could also be applied to basic science applications, such as correlating the tissue structure identified by OCT to certain disease states, given a larger sample size of hearts with AF. The tissue structure identified by OCT data could also be incorporated into tissuespecific, electrophysiological models to better understand the influence of tissue microstructure on AF dynamics [20].…”

Real‐time optical spectroscopic monitoring of nonirrigated lesion progression within atrial and ventricular tissues

“…Several groups have proposed optical methods for evaluating acute thermal injury immediately following radiofrequency (RF) treatment. In ventricular tissue, direct visualization of the myocardium by optical coherence tomography (OCT) has been shown to reliably discriminate between ablated, necrotic tissue and untreated tissue . However, the inherent depth limitation of OCT (<1 mm in cardiac tissue) renders the technique unsuitable for lesion transmurality assessment.…”

Characterization of the human myocardium by optical coherence tomography

“…Combined with optical clearing or thick sectioning methods, OCT imaging could provide large‐scale image maps of tissue microstructure transmurally through the cardiac wall. These image maps could also be combined with computational modeling to investigate structure‐function relationships .…”