Substrates of Sudden Cardiac Death in Hypertrophic Cardiomyopathy

Figures

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  Figure 1. The figure shows a short-axis view of a CMR of a patient with HCM, highlighting an extensive scar involving the anterior wall and the interventricular septum. LGE-CMR images were post-processed using ADAS 3D (Galgo Medical, Barcelona, Spain), creating nine concentric surface layers spanning from the endocardium to the epicardium of the left ventricular wall thickness, resulting in a 3D shell for each layer. Color-coded pixel signal intensity (PSI) maps were projected onto each shell. Hyper-enhanced areas were classified as the core zone, borderline zone (BZ), or healthy tissue using thresholds of 40 ± 5% and 60 ± 5% of the maximum PSI. The scar-dense core is coded in red, BZ is coded in orange and white, and healthy myocardium is coded in blue. BZ channels are identified as continuous corridors of BZ protected by scar core tissue. In (A), the 50% layer is shown, representing the mid-myocardial layer. The area is entirely occupied by a dense and compact scar. In (B), the 3D reconstruction corresponds to the 80% epicardial layer. In the anterior wall, at the center of the crosshair, a BZ channel is visible.

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  Figure 2. Induction of ventricular fibrillation by programmed ventricular stimulation (PVS) in a patient with HCM. A basic drive train cycle length of 430 ms is followed by three extra stimuli with short coupling intervals (220, 200, and 200 ms) applied in the right ventricle. The prognostic significance of polymorphic VT and VF induced with PVS in HCM is unknown. Aggressive stimulation protocols may lack specificity when identifying true arrhythmic risk.