Endocrine Abstracts

Case history: We present the case of a 70-year-old female who presented to the Emergency Department with sudden onset inter-scapular and upper abdominal pain. She had been experiencing intermittent headaches, palpitations and constipation which had not previously been investigated. The only past medical history was of hypothyroidism. She had no significant family history. There was a discrepancy in the blood pressure between both arms. Admission blood pressure was elevated at 146/88 mm Hg on the left and 120/80 mm Hg on the right.

Investigations: Admission ECG showed ST depression in the inferolateral leads. Troponin T was elevated (488 ng/l; normal <14) but other baseline bloods were normal. An urgent CT aortic angiogram was arranged which showed no evidence of dissection but an incidental left adrenal partially cystic mass of 7.4×7.3 cm. Echocardiogram revealed no left ventricular hypertrophy but a severely hypokinetic basal inferior segment with severe mitral regurgitation. Urgent angiogram showed normal coronary arteries. Interestingly, repeat troponin T assay 48 hours later had reduced markedly to 246 ng/l. Endocrinology review was sought and further investigations revealed elevated plasma metadrenaline >9000 pmol/l (normal range <510), normetadrenaline >40000 pmol/l (<1180), and 3-methoxytyramine 1732 pmol/l (<120). 24 hour urinary catecholamines were also significantly raised, with volume 1856 ml, normetadrenaline 95.1 umol/24 h (normal <3.3), metadrenaline 21 umol/24 h (0.1–1.2) and methoxytyramine 5.36 umol/24 h (normal <2). Aldosterone-renin ratio and 1 mg overnight dexamethasone suppression test were normal. MIBG scan showed increased uptake in the left adrenal gland consistent with a diagnosis of phaeochromocytoma.

Results and treatment: Phenoxybenzamine was initiated and titrated to 30 mg twice daily which improved her symptoms. She went on to have a successful laparoscopic adrenalectomy with no perioperative complications. Histology confirmed adrenal phaeochromocytoma with necrotic area and no obvious malignancy. Patient is awaiting a repeat echocardiogram, cardiac MRI and genetic work up.

Conclusions and points for discussion: Takotsubo syndrome mimics an acute coronary syndrome with ischaemic ECG changes, myocardial enzyme elevation, chest pain and echocardiographic abnormalities. Coronary angiogram is usually normal. Increased catecholamine release due to phaeochromocytoma is a recognised trigger, although rare. Other cardiovascular manifestations of phaeochromocytoma include myocardial infarction, arrhythmia and cardiac failure. Secondary takotsubo syndrome due to phaeochromocytoma should be considered especially in the context of normal coronary arteries and treatment resistant hypertension.