Autoimmune polyendocrine syndrome II presenting paradoxically as Takotsubo cardiomyopathy: A case report and reappraisal of pathophysiology

Abstract

Abstract BackgroundTakotsubo cardiomyopathy (TCM) is a rare disease entity characterized by acute, non-ischemic, reversible myocardial dysfunction that mimics acute myocardial infarction. Activation and excessive outflow of sympathetic nervous system is believed to be central to the figure in the disease pathogenesis. Adrenocortical hormones potentiate the systemic actions of sympathetic nervous system and accordingly are essential for regulation of myocardial function. We present an unusual case of a middle-aged woman with primary adrenal insufficiency who presented paradoxically with TCM. Case presentation A 50-year-old woman with past history of hypothyroidism presented to emergency department with history of acute chest pain and syncope. There was no significant drug history or history of an emotional or physical stimulus prior to admission. Prominent pigmentation over the tongue and skin creases of hands were noted. On presentation she was in shock and had ventricular tachycardia which required electrical cardioversion. The subsequent electrocardiogram demonstrated diffuse T-wave inversions with prolonged QTC. There was apical hypokinesia on echocardiogram and cardiac biomarkers were elevated. There was persistent inotropic requirement. She had marked postural symptoms and a postural blood pressure drop of 50mm Hg was present. Initial laboratory parameters were significant for hyperkalemia (7.8mEq/L) and hyponatremia (128mEq/L). These findings prompted evaluation for adrenal insufficiency which was confirmed with appropriate tests. Autoimmune polyendocrine syndrome II was thus diagnosed based on the above findings. Coronary angiography revealed normal coronaries. The diagnoses of TCM was established in accordance with the International takotsubo diagnostic criteria. She was started on stress dose steroid replacement therapy and improved dramatically. At one month of follow-up, the patient is asymptomatic and there was normalization of her left ventricular function. ConclusionsIntricate relationship and interplay exist between the steroid hormones and catecholamines in the pathogenesis of TCM. Steroid hormones not only potentiate the actions of catecholamines, they also regulate and channelize catecholaminergic actions preventing their deleterious effects on the cardiac tissue. Hence, both steroid deficiency and exogenous steroid replacement may precipitate TCM. Evidence from more such cases and larger perspective studies in the future will further improve our understanding of this complex disease process and its myriad associations.