Sudden cardiac death due to adrenal insufficiency masquerading as Brugada syndrome. Case report

Sudden cardiac death in young people in 20% of cases is caused by cardiomyopathies and channelopathies. One of the forms of channelopathies is Brugada syndrome, a hereditary disease characterized by ST segment elevation in the right precordial leads (V1-V3) and an increased risk of sudden cardiac death in the absence of structural heart disease. Brugada phenocopies are also known – clinical situations that are manifested by electrocardiogram (ECG) patterns identical to true Brugada syndrome. They are caused by different clinical circumstances and form a group of heterogeneous conditions that are often difficult to distinguish from true congenital Brugada syndrome due to identical ECG patterns. The formation of Brugada phenocopy due to hyperkalemia is presented in the literature in various conditions: with renal failure, after extensive trauma, application of medications. The article presents a case report demonstrating a rare cause of sudden cardiac arrest in a young patient without a history of cardiovascular pathology: the occurrence of the Brugada pattern on the ECG due to severe hyperkalemia in adrenal insufficiency. The stages of the differential diagnostic search are described, which made it possible to verify the final diagnosis and prescribe effective hormone replacement therapy. Performing a provocative test with novocanamide allowed us to confirm that the patient had a phenocopy, and not Brugada syndrome. Differential diagnosis of phenocopies of Brugada syndrome – a series of often life-threatening cardiac and non-cardiac diseases and conditions, manifested by similar ECG changes in the form of a peculiar ST segment elevation in leads V1-V3, is often a difficult task. This case represents a phenocopy of Brugada in the setting of severe hyperkalemia with development of cardiac arrest due to adrenal insufficiency, which resolved with correction of electrolyte abnormalities and treatment of the underlying disease. Typical ECGs are presented: a graph of the Brugada phenomenon, hyperkalemia, a sinusoidal curve during cardiac arrest, recorded over time in a patient, and the pathogenetic mechanisms causing the formation of the Brugada pattern in adrenal insufficiency are explained.