Journal of Clinical Case Reports

Unmasking of Occult Myasthenia Gravis in Hypertrophic Cardiomyopathy by Beta Blockers

Abstract

Srivatsa Nadig, Aditya Kapoor, Ritesh Agrawal and Anjali Mishra

Association of Hypertrophic cardiomyopathy (HCM) with immune linked disorders like myasthenia gravis is extremely rare. Various pharmacologic agents can potentially precipitate or unmask underlying signs and symptoms of myasthenia gravis. Oral beta blockers are an important mainstay in the pharmacological management of patients with HCM. We report a case of obstructive HCM who when treated with beta blockers developed increasingly severe weakness and fatigue. Detailed clinical examination led to a clinical diagnosis of underlying myasthenia gravis which was secondary to a thymoma. The patient had developed acute unmasking of the latent myasthenia gravis following institution of therapy with beta-blockers. The patient underwent successful resection of the thymic mass and made an uneventful recovery. Symptoms like fatigue, shortness of breath and weakness are common among patients with HCM and are also frequent in patients with myasthenia gravis, sometimes making a clinical diagnosis difficult. It is important for physicians to be aware of such unusual associations to be able to appropriately manage such cases in clinical practice.