Cardiac tamponade as initial presenting feature of primary hypothyroidism in the ED

Pericardial effusion is commonly detected in patients with severe hypothyroidism and is typically mild; rarely, it may lead to cardiac tamponade. Cardiac tamponade with myxedema coma as initial presenting feature of previously unrecognized hypothyroidism is rare. This case highlights that previously undiagnosed hypothyroidism can manifest as myxedema coma with shock due to pericardial tamponade particularly in winters because a cold environment can precipitate myxedema.We report an undiagnosed case of primary hypothyroidism who presented to the emergency department for the first time with both cardiac tamponade and myxedema coma. This combination of cardiac tamponade and myxedema coma as the presenting features of primary hypothyroidism has rarely been reported in the literature. The patient was effectively managed with echocardiography-guided pericardiocentesis, levothyroxine, and external rewarming. Cardiac tamponade and myxedema coma as presenting features of previously unrecognized primary hypothyroidism are extremely rare. Urgent bedside echocardiography with pericardiocentesis along with thyroxine therapy is the treatment of choice. It is important to include hypothyroidism as the differential diagnosis in patients with cardiac tamponade and altered level of consciousness especially in winter months.