Endocrine Abstracts

A 63-year-old female with cardiovascular risk factors presented with tremor, sweating, lower back discomfort, nausea and dyspnoea. ECG showed sinus tachycardia with lateral ST-depression. High-sensitivity troponin was dynamically elevated (72 ng/l to 112ng/l on one-hour repeat). Computed tomography aortogram ruled out aortic dissection but identified a 6.6cm lesion in the left adrenal gland. Ventricular tachycardia was detected on cardiac monitoring. Differential diagnoses included acute coronary syndrome and a pheochromocytoma (with arrhythmia and myocardial injury). Invasive coronary angiography demonstrated non-obstructive coronary artery disease. Post-procedure, the patient developed a pheochromocytoma crisis. This was managed with intravenous phentolamine. Our case serves as an important reminder that invasive procedures in these patients can induce potentially life-threatening hyperadrenergic episodes. Pheochromocytomas are usually benign tumours, arising from the chromaffin cells in the adrenal medulla or a paraganglion. The vast majority are hormonally active, secreting catecholamines. The resulting hyperadrenergic state causes the classic triad of symptoms; paroxysms of tremor, headache and diaphoresis. However, presentation can be varied and may mimic other conditions. They are rare, with an estimated annual incidence of 2 – 8 per million population, although this is likely an underestimation based on post-mortem studies and increasing pre-symptomatic diagnosis rates. Whilst most are sporadic cases, at least a third occur as part of a familial syndrome (e.g. von Hippel-Lindau, MEN-2, neurofibromatosis-1). Treatment is firstly medical, but in the absence of metastatic disease, cure can be achieved with surgical resection. Prior to surgery, patients need to be adequately alpha-blocked, typically for 7–14 days with phenoxybenzamine. Lifestyle advice to increase sodium and fluid intake is important pre-operatively to prevent hypotension after resection. Beta-blockers are contraindicated initially as unopposed beta-blockade can trigger a hypertensive crisis, but can be commenced after adequate alpha-blockade. Suggested treatment of a hypertensive crisis is with intravenous phentolamine boluses followed by infusion as required for maintenance of responsee. There have been a number of published case reports showing pheochromocytomas presenting with chest pain, ECG changes and raised cardiac biomarkers mistakenly being investigated and treated as acute coronary syndromes (ACS).[e.g. 5-7] Given the rarity of pheochromocytomas and how common coronary heart disease is, this presentation understandably can lead to delays in the correct diagnosis. Our case report is therefore an important reminder that in those patients with confirmed or suspected pheochromocytomas, invasive procedures such as coronary angiography can trigger hyperadrenergic crises.