Tako-Tsubo Cardiomyopathy and Thyroid Dysfunction

First described in a Japanese population in 1991, the Tako-Tsubo disease has recently been included among the primary acquired cardiomyopathies in the American Heart Association's disease classifications. Tako-Tsubo cardiomyopathy (TTC) is a reversible, often misdiagnosed condition, as it can easily mimic acute coronary syndrome. It has indeed been estimated that TTC can represent 1 to 2% of patients who present with suspected acute coronary syndrome. The disease is especially common in women. In its typical presentation, the identifying characteristic of TTC is the systolic bulging of the heart's apex with preserved contraction of basal myocardial segments. The acute left ventricular dysfunction, however, it is usually reversible, with contractile function usually recovering in a few weeks. The etiology of TTC is not completely clear. Many theories have been proposed, taking into account the role of hormone disturbances, acute toxic effects of catecholamines on cardiomyocytes, diffuse microvascular spasms, multivessel epicardial spasms, and acute myocarditis. Several researchers have suggested that TTC may occur as a rare complication of dysthyroidism. In particular, an acute hyperthyroid state has been proposed to be capable of triggering TTC, independently of its causes. Indeed, several cases of TTC associated with Graves' disease, Hashimoto thyroiditis, or excess levothyroxine therapy have been reported in the medical literature. The mechanism by which dysthyroidism can trigger TTC, however, remains poorly understood. In this review we investigated the role of thyroid dysfunction as a possible trigger for TTC.