Calcium release deficiency syndrome, a rare variant of catecholaminergic polymorphic ventricular tachycardia

Authors present a difficult-to-diagnose clinical case of cotecholaminergic polymorphic ventricular tachycardia (CPVT), a rare hereditary disease, which is characterized by mutations most often in the RYR2 gene with increased function of the ryanodine receptor, which in its turn is the main protein of calcium channels in the sarcoplasmic reticulum of cardiomyocytes. The mechanism of development of the pathology is based on late post-depolarization, which is a trigger for the occurrence of severe ventricular arrhythmias associated with a high risk of sudden cardiac death. Ventricular arrhythmias in children with CPVT can causally be reproduced using an exercise test at a low heart rate threshold. However, there have been reports of sudden cardiac death in individuals who had the loss-of-function RyR2 mutations and who have nevertheless had negative stress test results. The main clinical manifestation is syncope, the genesis of which may remain unknown for a long time. The described clinical case demonstrates the complexity of diagnosis, for which the routine cardiological examination isn’t enough. Specialists therefore have difficulties in making the correct diagnosis and determining the patient management tactics.