Delayed-enhanced MR scar imaging and intraprocedural registration into an electroanatomical mapping system in post-infarction patients

Abstract

Post-infarction arrhythmias are most often confined to scar tissue. Scar can be detected by delayed-enhanced cardiac magnetic resonance. The purpose of this study was to assess the feasibility of pre-procedural scar identification and intraprocedural real-time image registration with an electroanatomical map in 23 patients with previous infarction and ventricular arrhythmias (VAs). Registration accuracy and cardiac magnetic resonance/electroanatomical map correlations were assessed, and critical areas for VA were correlated with the presence of scar. With a positional registration error of 3.8 ± 0.8 mm, 86% of low-voltage points of the electroanatomical map projected onto the registered scar. The delayed-enhanced cardiac magnetic resonance-defined scar correlated with the area of low voltage (R = 0.82, p < 0.001). All sites critical to VAs projected on the registered scar. Selective identification and extraction of delayed-enhanced cardiac magnetic resonance defined scar followed by registration into a real-time mapping system are feasible and help to identify and display the arrhythmogenic substrate in post-infarction patients with VAs.

Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1. Short-axis stack of delayed enhanced magnetic resonance images showing a region of scar in the lateral left ventricle

Figure 2. A series of three images of electroanatomical maps and 3 –D reconstruction of scar and left ventricular endocardium

Left panel: voltage map with a cut-off voltage of 1.5 mV. Middle panel: merged endocardial MRI shell (blue color) with scar shell (green color) Right panel: merged MRI scar (green color) with electroanatomical map.