Catheter Ablation -> Ventricular Arrhythmias -> Mapping & Imaging D-PO06 - Poster Session VI (ID 26) Poster

D-PO06-095 - Integration Of Whole Heart Histology: A Novel Method For The Direct Comparison Of Histology With Electrophysiological And Imaging Data (ID 661)


Background: Advancements in delineation of VT substrates (imaging/mapping) are rarely validated by histology - the true gold standard. When histological validation is performed, a side-by-side approach is usually used resulting in significant error. Deformation of the heart also often hampers comparisons.
Objective: Method for histological validation of EP/imaging data.
Methods: After death the heart is excised and rinsed (fig A). The chambers are filled with a cold polymer, HistOmer, to maintain diastolic dimensions (fig B). The heart is fixed with formaldehyde. The fixed heart is placed in an MRI-compatible box and filled with HistOmer (Fig C). The heart can be imaged, HistOmer is MRI compatible (fig E). The block of HistOmer is placed in the HistOtech Quick Slicer Flex and sliced (fig F). Photographs of the slices (fig F) are processed as a DICOM file and imported into MASS (MASS, Leiden, NL) where the cardiac contours can be traced and exported as .vtks which are imported in CARTO and merged with in-vivo mapping data (Fig F) using landmarks (ablation lesions/anatomical landmarks).
Results: Once merged, data is exported and visualized in either MASS or Paraview (Kitware Inc., New York). Slices stored in alcohol-glycerine (Fig J). Locations on gross pathological slices corresponding to either EP data points or to imaging locations of interest (fig I) are excised and processed in a standard histology lab (fig H).
Conclusion: This approach is simple and easily reproduced. Filling the chambers preserves cardiac dimension and using landmarks to merge 3D structures removes the inaccuracies of side-by-side comparison.