Pheochromocytoma and Thyroid Storm Presenting as ST-Elevation Myocardial Infarction in a Patient with Non-Obstructive Coronary Arteries.

Introduction: Pheochromocytomas can present as a diagnostic challenge, given their diverse clinical manifestations. Though classically taught as presenting with headaches, palpitations and paroxysmal hypertension, only 1 in 4 present with such a triad. Catecholamines affect the myocardium in various ways, ranging from beta-adrenergic receptor-mediated myofibril dysfunction to direct myocardial injury by catecholamine oxidation products.

Case Description: We report the case of a 41-year-old female with no significant past medical history, who presented with acute coronary syndrome. She was found to have myocardial infarction with non-obstructive coronary arteries (MINOCA), and her clinical course was complicated by erratic blood pressure management. Laboratory findings and imaging findings confirmed the diagnosis of pheochromocytoma. Post-cardiac catheterisation, she developed a thyroid storm and fatal cardiac arrest.

Conclusions: The combination of hyperthyroidism with pheochromocytoma is rare but often fatal; iodinated angiography contrast likely precipitated her thyroid storm. This case underscores the importance of considering pheochromocytoma early in patients with MINOCA, particularly in those with erratic blood pressure. Pheochromocytomas have been reported to be associated with MINOCA in rare cases and have significant mortality. Current guidelines do not include pheochromocytoma as a possible differential diagnosis; recognition and early diagnosis are crucial for improved outcomes.

Learning Points: Pheochromocytoma and thyroid disease should be added as recommended differential diagnoses in patients with myocardial infarction with non-obstructive coronary artery disease (MINOCA) despite current guidelines not including them in the routine work-up.For patients with erratic blood pressure and MINOCA, the possibility of a pheochromocytoma should be considered early, as a prompt diagnosis can result in favourable outcomes.