Abstract 17870: Cardiac Computed Tomography Guides Ventricular Tachycardia Ablation
Background: Cardiac MRI characterizes scar tissue and identifies the heterogeneous zones (HZ) which may represent target vulnerable myocardium that guides ventricular tachycardia (VT) ablation strategies. Unfortunately, cardiac MRI is often contraindicated due to implantable devices. Cardiac computed tomography (CT) also characterizes tissues and has the advantage of being able to be used with implantable devices; however, its role for VT ablation is emerging and has only been defined with delayed enhancement which requires two acquisitions.
Methods: We performed CT in 3 consecutive patients undergoing VT ablations. Non-delayed LV images were processed into 17-segment bulleyes and further partitioned into 2880 detailed sub-segments to generate Hounsfield units (HU) polar maps and colour-scale overlays to enhance subtle transitions of attenuation in order to define HZ (Vitrea®). During electrophysiology study (EPS), an endocardial bipolar voltage map of the LV was created using a 3D electroanatomical mapping system with a standard voltage criteria (scar <0.5mV in red and healthy >1.5mV in purple) and this was compared to the CT.
Results: Single acquired CT accurately identified the HZ and correlated to the voltage map ascertained by the mapping system. Figures: A-VT morphology. B-Polar map with averaged-HU identifying basal inferior and inferolateral segments as HZ zone. C-CT image of the LV basal inferior aneurysm. D-Endocardial bipolar voltage map with excellent correlation to the CT. The critical isthmuses of VTs in all 3 patients determined during EPS localized to the same HZ identified on CT. Radiofrequency ablation successfully terminated the VT with acute non-inducibility.
Conclusion: Cardiac CT with enhanced 2880 sub-segmental attenuation analysis defines HZ zones, cardiac anatomy, function, guides successful VT ablation with single acquisition, less radiation and has the potential to improve or have advantages to delayed enhancement techniques.
Author Disclosures: K.C. Chua: None. R.P. Karlsberg: None. E.S. Gang: None.
- © 2016 by American Heart Association, Inc.