Quantitative Analysis of Electro-Anatomical Maps: Application to an Experimental Model of Left Bundle Branch Block/Cardiac Resynchronization Therapy

Abstract

Electro-anatomical maps (EAMs) are commonly acquired in clinical routine for guiding ablation therapies. They provide voltage and activation time information on a 3-D anatomical mesh representation, making them useful for analyzing the electrical activation patterns in specific pathologies. However, the variability between the different acquisitions and anatomies hampers the comparison between different maps. This paper presents two contributions for the analysis of electrical patterns in EAM data from biventricular surfaces of cardiac chambers. The first contribution is an integrated automatic 2-D disk representation (2-D bull’s eye plot) of the left ventricle (LV) and right ventricle (RV) obtained with a quasi-conformal mapping from the 3-D EAM meshes, that allows an analysis of cardiac resynchronization therapy (CRT) lead positioning, interpretation of global (total activation time), and local indices (local activation time (LAT), surrogates of conduction velocity, inter-ventricular, and transmural delays) that characterize changes in the electrical activation pattern. The second contribution is a set of indices derived from the electrical activation: speed maps, computed from LAT values, to study the electrical wave propagation, and histograms of isochrones to analyze regional electrical heterogeneities in the ventricles. We have applied the proposed methods to look for the underlying physiological mechanisms of left bundle branch block (LBBB) and CRT, with the goal of optimizing the therapy by improving CRT response. To better illustrate the benefits of the proposed tools, we created a set of synthetically generated and fully controlled activation patterns, where the proposed representation and indices were validated. Then, the proposed analysis tools are used to analyze EAM data from an experimental swine model of induced LBBB with an implanted CRT device. We have analyzed and compared the electrical activation patterns at baseline, LBBB, and CRT stages in four animals: two without any structural disease and two with an induced infarction. By relating the CRT lead location with electrical dyssynchrony, we evaluated current hypotheses about lead placement in CRT and showed that optimal pacing sites should target the RV lead close to the apex and the LV one distant from it.

A dual adaptive explicit time integration algorithm for efficiently solving the cardiac monodomain equation

“…Taking OST as a reference, both DAETI and OSTAR rendered error values of e LAT and e APD of the order of E‐3 and E‐4, respectively, at infarct and LBBB conditions. The activation pattern characteristic of LBBB conditions, as well as the longer time required to fully complete ventricular activation under these conditions, were well represented by DAETI, OSTAR and OST, providing results in agreement with previously published data 23,27 …”

“…A tetrahedral mesh representation of the biventricular swine anatomy (273919 nodes, 1334218 elements) was made available from the CRT‐EPiggy19 challenge 20,21 . It was part of a swine model dataset of LBBB for experimental studies of cardiac resynchronization therapy 22,23 . A homogeneous diffusion coefficient d 0 = 0.002 cm 2 /ms was set across the cardiac tissue, with a transverse‐to‐longitudinal conductivity ratio of ρ = 0.25.…”

“…20,21 It was part of a swine model dataset of LBBB for experimental studies of cardiac resynchronization therapy. 22,23 A homogeneous diffusion coefficient d 0 = 0.002 cm 2 /ms was set across the cardiac tissue, with a transverse-to-longitudinal conductivity ratio of ρ = 0.25. For the myocardial infarction simulation, the scar region was located at the left anterior part of the left ventricle's apex and was assumed as zero conductive tissue.…”

Comparative Anesthesia Effect of Brachial Plexus Block Based on Smart Electronic Medical Ultrasound-Guided Positioning and Traditional Anatomical Positioning

“…The transducer has an inverse piezoelectric effect; that is, electrical energy generates mechanical energy, and its surface will produce high-frequency compression and expansion. Drive the surrounding medium to vibrate together, so ultrasonic waves are generated [ 10 , 11 ]. Ultrasound imaging is widely used because of its many advantages, but speckle gives ultrasound images its unique granular appearance.…”

Influence of Left Bundle Branch Block on the Electrocardiographic Changes Induced by Acute Coronary Artery Occlusion of Distinct Location and Duration

“…The reliability of the swine model of LBBB used in this study is based on: (a) the abrupt increase in QRS complex duration and appearance of R waves with secondary ST segment changes in precordial leads, and (b) the development of an abnormal LV contraction pattern comparable to that observed in patients with LBBB as was described in a similar swine model (Rigol et al, 2013). Moreover, the characteristic delay in the interventricular septal activation found in patients with LBBB has been also confirmed by LV electroanatomical mapping recordings in pigs with ablation induced LBBB (Soto Iglesias et al, 2017).…”