A young woman presented to the emergency department complaining of palpitation, faintness, and dyspnoea. She had, 12 years earlier, undergone a successful and uncomplicated radiofrequency ablation of a left posterolateral accessory atrioventricular pathway by the retrograde transaortic approach. The transthoracic echocardiogram showed a large spherical mass on the lateral left ventricular wall. A computed tomography scan confirmed the presence of a large, partially calcified pseudoaneurysm containing a thrombus, on the left lateral ventricular wall, near the circumflex artery and the mitral annulus (Panel A). A 3D reconstruction of the scan showed a 37 mm deep and 44 mm wide pseudoaneurysm (Panel B). The neck of the pseudoaneurysm at precisely the point of radiofrequency energy delivery and the characteristics of the lesion were strongly suggestive of...

This is our second article devoted to the cardiac myoarchitecture considered as a nematic chiral liquid crystal (NCLC). While the first article focused on the myoarchitecture of the left ventricle (LV), this new article extends to the whole ventricular mass and introduces the concept of disclinations and topological singularities, which characterize the differences and relationships between the left and right ventricles (RV). At the level of the ventricular apices, we constantly observed a vortex shape at the LV apex, corresponding, in the terminology of liquid crystals, to a “+1 disclination”; we never observed this at the RV apex. At the level of the interventricular septum (IVS), we identified “−1/2 disclinations” at the anterior and posterior parts. During the perinatal period, there was a significant difference in their distribution, with more “−1/2 disclinations” in the posterior part of the IVS. After birth, concomitant to major physiological changes, the number of “−1/2 disclinations” significantly decreased, both in the anterior and posterior parts of the IVS. Finally, the description of the disclinations must be considered in any attempt to segment the whole ventricular mass, in biomechanical studies, and, more generally, for the characterization of myocardial remodeling.

This article is the third in our series dedicated to the analysis of cardiac myoarchitecture as a nematic chiral liquid crystal (NCLC). Previously, we introduced the concept of topological defects (disclinations) and focused on their visual identification inside the compact myocardium. Herein, we investigate these using a mathematical and automated algorithm for the reproducible identification of a larger panel of topological defects throughout the myocardium of 13 perinatal and 11 early infant hearts. This algorithm identified an average of 29 ± 11 topological defects per slice with a 2D topological charge of m = +1/2 and an average of 27 ± 10 topological defects per slice with a 2D topological charge of m = −1/2. The excess of defects per slice with a 2D topological charge of m = +1/2 was statistically significant (p < 0.001). There was no significant difference in the distribution of defects with a 2D topological charge of m = +1/2 and m = −1/2 between perinatal and early infant hearts. These defects were mostly arranged in pairs, as expected in nematics, and located inside the trabecular myocardium. When isolated, defects with a 2D topological charge of m = +1/2 were located near the luminal extremity of the trabeculae and those with a 2D topological charge of m = −1/2 were located at the anterior and posterior part of the interventricular septum. These findings constitute an advance in the characterization of the deep cardiac myoarchitecture for application in developmental and pathological studies.