Abstract 19831: Local Myocardial Intensity on Cardiac Computed Tomography is Associated With Scar Substrate in Post-Infarct Ventricular Tachycardia
Introduction: Catheter ablation of post-infarct ventricular tachycardia (VT) reduces risk of recurrent ICD shocks but long-term success rates are suboptimal. Contrast enhanced CT (CE-CT) can identify perfusion defects that may be associated with arrhythmia substrate.
Hypothesis: Local CE-CT myocardial attenuation density (AD) is associated with intra-cardiac voltage, a marker of VT substrate.
Methods: Fifteen patients with post-infarct VT who underwent pre-ablation multi-detector CE-CT were included. Electroanatomic mapping (EAM) was performed during sinus rhythm. EAM points were registered to CE-CT images (Figure). Mean AD within 5, 10, and 15 mm of each EAM point was quantified using MATLAB (Natick, MA), excluding points falling on areas of artifact. Voltage data was log transformed due to data skew. The association of electrogram (EGM) voltage and local AD was examined using multi-level mixed effects linear regression with data clustering per patient. The log-restricted likelihood (LRL) with higher value (closer to zero) was utilized to select the best model fit.
Results: A total of 4,994 EAM points were analyzed. Of all points, 37% were consistent with scar (<0.5 mV) and 33% with border zone (0.5 mV - 1.5 mV). Log bipolar voltage was associated with local AD using an analysis radius of 10mm (coefficient 0.29 per 100 HU, P<0.001, LRL -7380) and 15mm (0.45, P<0.001, LRL -7372). Log unipolar voltage was associated with local AD using an analysis radius of 5mm (0.11, P<0.001, LRL-3390), 10mm (0.27, P<0.001, LRL -3350), and 15 mm (0.34, P<0.001, LRL -3339).
Conclusion: The association of myocardial attenuation density on CE-CT with EGM voltage in patients with post-infarct VT varies based on the analysis radius from each point. In this cohort an analysis radius of 15 mm provided the best model fit for both bipolar and unipolar voltage. Analysis of CE-CT data may offer insight into the field of view of each point on catheter mapping and an opportunity for pre-procedural planning.
Author Disclosures: S. Misra: None. S. Zahid: None. A. Prakosa: None. E.G. Ipek: None. T. Zghaib: None. H. Tandri: None. D. Spragg: None. J.E. Marine: None. A. Kolandaivelu: None. R. Berger: None. N. Trayanova: Ownership Interest; Modest; CardioSolv, LLC.. H. Calkins: None. H. Halperin: None. S. Zimmerman: None. S. Nazarian: Research Grant; Significant; Biosense Webster. Consultant/Advisory Board; Significant; Biosense Webster.
- © 2016 by American Heart Association, Inc.