6966 A Rhythmic Life-Threatening Enigma Unveiled: KCNH2 Mutation-Associated Torsades de Points Unmasking Primary Hyperaldosteronism in Cardiological Realm

Abstract Disclosure: S. Dejprapasorn: None. N. Nopparatana: None. S. Soonthornpun: None. R. Leelawattana: None. N. Kietsiriroje: None. S. Limumpornpetch: None. T. Nilmoje: None. W. Lohawijarn: None. T. Wongsuttipakorn: None. P. Choochuen: None. P. Limumpornpetch: None. Introduction: Primary hyperaldosteronism (PA) is characterized by hypertension and hypokalemia. However, its ability to masquerade life-threatening Torsades de Pointes makes it an unusual and dismissed diagnosis, revealing the link between PA and serious arrythmia. Clinical Case A 30-year-old female experienced three episodes of palpitations, followed by syncope. Upon admission, her blood pressure was 147/87 mmHg. ECG showed prolonged QT intervals with potassium level was 2.6 mmol/L (3.5-5.0 mmol/L). Continuous cardiac monitoring captured Torsades de Pointes. Despite potassium replacement, long QT still persisted. Pathogenic variant, c.2592+1G>A, within KCNH2 was discovered. Aldosterone concentration showed 69.65 ng/dL (9.70-62.60 ng/dL) and plasma renin activity was 0.12 ng/mL/h (1.50-5.70 ng/mL/h). Aldosterone-to-renin ratio was 580. Aldosterone post 4-h saline infusion test was 31.71 ng/dL which were consistent with PA. Adrenal unenhanced CT scan identified bilateral adrenal nodules (right 1.3 cm, left 1.1 cm). After receiving a cardioverter-defibrillator and spironolactone, the patient has had no palpitations, and their potassium level has remained normal. Clinical lessons: PA rarely presents ventricular arrhythmia. KCNH2 mutation may link between long QT syndrome (LQTS) and PA arises. LQTS type 2 is attributable to KCNH2 mutations, impacting potassium channel subunits crucial for adjusting currents during sympathetic activation. This is essential for shortening the QT interval with increasing heart rate. KCNH2 mutations disrupt this process, prolonging the QT interval and heightening the risk of arrhythmias. Aldosterone synthesis relies on calcium signaling triggered by potassium currents. Adrenal cortex hosts approximately 90 potassium channels genes, including KCNJ5 and KCNH2. Mutations in gene can disrupt the calcium signaling cascade, leading to excessive aldosterone production. While KCNJ5 mutation is well-documented in PA, the potential correlation between KCNH2 mutations and a similar mechanism remains unexplored in clinical reports to date. This case highlights the importance of a thorough comprehension of genetic cause contributing to pathogenesis of PA with complex clinical presentations. Presentation: 6/1/2024