AUTHOR=Perez-Alday Erick A. , Haq Kazi T. , German David M. , Hamilton Christopher , Johnson Kyle , Phan Francis , Rogovoy Nichole M. , Yang Katherine , Wirth Ashley , Thomas Jason A. , Dalouk Khidir , Fuss Cristina , Ferencik Maros , Heitner Stephen , Tereshchenko Larisa G. 

TITLE=Mechanisms of Arrhythmogenicity in Hypertrophic Cardiomyopathy: Insight From Non-invasive Electrocardiographic Imaging

JOURNAL=Frontiers in Physiology

VOLUME=Volume 11 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2020.00344

DOI=10.3389/fphys.2020.00344

ISSN=1664-042X

ABSTRACT=Background—Mechanisms of arrhythmogenicity in hypertrophic cardiomyopathy (HCM) are not well understood. 
Objective—To characterize an electrophysiological substrate of HCM in comparison to ischemic cardiomyopathy (ICM), or healthy individuals.
Methods—We conducted a prospective case-control study. The study enrolled HCM patients at high risk for ventricular tachyarrhythmia (VT) (n=10; age 61±9 y; left ventricular ejection fraction (LVEF) 60±9%), and three comparison groups: healthy individuals (n=10; age 28±6 y; LVEF>70%), ICM patients with LV hypertrophy (LVH) and known VT (n=10; age 64±9 y; LVEF 31±15%), and ICM patients with LVH and no known VT (n=10; age 70±7y; LVEF 46±16%). All participants underwent 12-lead ECG, cardiac CT or MRI, and 128-electrode body surface mapping (BioSemi ActiveTwo, Netherlands). Non-invasive voltage and activation maps were reconstructed using the open-source SCIRun (University of Utah) inverse problem-solving environment.
Results—In the epicardial basal anterior segment, HCM patients had the greatest ventricular activation dispersion [16.4±5.5 vs. 13.1±2.7 (ICM with VT) vs. 13.8±4.3 (ICM no VT) vs. 8.1±2.4 ms (Healthy); P=0.0007], the largest unipolar voltage [1094±211 vs. 934±189 (ICM with VT) vs. 898±358 (ICM no VT) vs. 842±90 µV (Healthy); P=0.023], and the greatest voltage dispersion [median(interquartile range) 215(161-281) vs. 189(143-208) (ICM with VT) vs. 158(109-236) (ICM no VT) vs. 110(106-168)µV (Healthy); P=0.041]. Differences were also observed in other endo-and epicardial basal and apical segments. 
Conclusion—HCM is characterized by a greater activation dispersion in basal segments, a larger voltage, and a larger voltage dispersion through LV.