Three-Dimensional 123I-Meta-Iodobenzylguanidine Cardiac Innervation Maps to Assess Substrate and Successful Ablation Sites for Ventricular Tachycardia: Feasibility Study for a Novel Paradigm of Innervation Imaging

• Published in: Circulation. Arrhythmia and electrophysiology Vol. 8; no. 3; pp. 583 - 591
• Main Authors: Klein, Thomas, Abdulghani, Mohammed, Smith, Mark, Huang, Rui, Asoglu, Ramazan, Remo, Benjamin F, Turgeman, Aharon, Mesubi, Olurotimi, Sidhu, Sunjeet, Synowski, Stephen, Saliaris, Anastasios, See, Vincent, Shorofsky, Stephen, Chen, Wengen, Dilsizian, Vasken, Dickfeld, Timm
• Format: Journal Article
• Language: English
• Published: United States American Heart Association, Inc 01.06.2015
• Subjects: 3-Iodobenzylguanidine; Action Potentials; Aged; Algorithms; Baltimore; Catheter Ablation - adverse effects; Electrophysiologic Techniques, Cardiac; Feasibility Studies; Female; Heart Ventricles - diagnostic imaging; Heart Ventricles - innervation; Heart Ventricles - surgery; Humans; Image Interpretation, Computer-Assisted; Imaging, Three-Dimensional; Male; Middle Aged; Predictive Value of Tests; Prospective Studies; Radionuclide Imaging; Radiopharmaceuticals; Sympathetic Nervous System - diagnostic imaging; Sympathetic Nervous System - physiopathology; Tachycardia, Ventricular - diagnostic imaging; Tachycardia, Ventricular - physiopathology; Tachycardia, Ventricular - surgery; Treatment Outcome; innervation; cardiac imaging techniques; tachycardia, ventricular
• ISSN: 1941-3149; 1941-3084
• DOI: 10.1161/CIRCEP.114.002105

BACKGROUND—Innervation is a critical component of arrhythmogenesis and may present an important trigger/substrate modifier not used in current ventricular tachycardia (VT) ablation strategies. METHODS AND RESULTS—Fifteen patients referred for ischemic VT ablation underwent preprocedural cardiac I- meta-iodobenzylguanidine (I-mIBG) imaging, which was used to create 3-dimensional (3D) innervation models and registered to high-density voltage maps. 3D I-mIBG innervation maps demonstrated areas of complete denervation and I-mIBG transition zone in all patients, which corresponded to 0% to 31% and 32% to 52% uptake. I-mIBG denervated areas were ≈2.5-fold larger than bipolar voltage–defined scar (median, 24.6% [Q1–Q3, 18.3%–34.4%] versus 10.6% [Q1–Q3, 3.9%–16.4%]; P<0.001) and included the inferior wall in all patients, with no difference in the transition/border zone (11.4% [Q1–Q3, 9.5%–13.2%] versus 16.6% [Q1–Q3, 12.0%–18.8%]; P=0.07). Bipolar/unipolar voltages varied widely within areas of denervation (0.8 mV [Q1–Q3, 0.3–1.7 mV] and 4.0 mV [Q1–Q3, 2.9–5.6 mV]) and I-mIBG transition zones (0.8 mV [Q1–Q3, 0.4–1.8 mV] and 4.6 mV [Q1–Q3, 3.2–6.3 mV]). Bipolar voltages in denervated areas and I-mIBG transition zones were <0.5 mV, 0.5 to 1.5 mV, and >1.5 mV in 35%, 36%, and 29%, as well as 35%, 35%, and 30%, respectively (P>0.05). Successful ablation sites were within bipolar voltage–defined scar (7%), border zone (57%), and areas of normal voltage (36%), but all ablation sites were abnormally innervated (denervation/I-mIBG transition zone in 50% each). CONCLUSIONS—I-mIBG innervation defects are larger than bipolar voltage–defined scar and cannot be detected with standard voltage criteria. Thirty-six percent of successful VT ablation sites demonstrated normal voltages (>1.5 mV), but all ablation sites were within the areas of abnormal innervation. I-mIBG innervation maps may provide critical information about triggers/substrate modifiers and could improve understanding of VT substrate and facilitate VT ablation. CLINICAL TRIAL REGISTRATION—URLhttp://www.clinicaltrials.gov. Unique IdentifierNCT01250912.