Investigation of the effect of HCM abnormalities on the ECG. (A) ECG morphologies of the HCM phenotypes studied: Group 1B with normal ECG morphology in V4–V6, Group 3 with QRS abnormalities with deep and wide S waves in V4–V6, and Group 1A with normal QRS morphology but inverted T waves in V4–V6. (B) Personalized 3D volumetric meshes of the heart and torso are computed for each representative patient. (C) The effect of HCM abnormalities (anatomy, tissue microstructure, conduction system, and ionic remodelling) on the ECG are investigated using computer simulations. CMR, cardiac magnetic resonance; ECG, electrocardiogram; HCM, hypertrophic cardiomyopathy.