Phaeochromocytomas are rare catecholamine-producing tumours which typically present with comparatively benign symptoms such as headache, palpitations, sweating, hypertension, and insulin resistance. In rare cases, severe cardiac manifestations have been reported. We describe a patient who developed severe hypoglycaemia after an oral glucose tolerance test (OGTT), potentially triggering a phaeochromocytoma crisis and cardiogenic shock. To the best of our knowledge, only four other cases of hypoglycaemia after OGTT have been reported in patients with phaeochromocytoma, of which none developed a phaeochromocytoma crisis.A 53-year-old woman with hypertension, dyslipidaemia, and prediabetes presented to the Emergency Department with hypoxia, hyperglycaemia, lactic acidosis, severe left ventricular dysfunction, and pulmonary oedema followed by cardiogenic shock. Onset of symptoms was only few hours after an OGTT during which she had developed severe transient hypoglycaemia. Angiography was performed due to elevated troponin levels and showed a midventricular contraction pattern typical of takotsubo. This was subsequently confirmed by cardiac magnetic resonance imaging. The patient's condition improved during the first 36 h and she was discharged home on Day 7. A positive catecholamine test prompted readmission to the Endocrinology Unit, where computer tomography confirmed the diagnosis of phaeochromocytoma. An adrenalectomy was performed, and the diagnosis was verified histopathologically.The possibility of a phaeochromocytoma must be considered as a potential triggering factor in patients presenting with takotsubo cardiomyopathy, in particular, when blood glucose levels fluctuate between severe hypo- and hyperglycaemia.
