Suspected Pheochromocytoma Precipitating Takotsubo Cardiomyopathy

Abstract

INTRODUCTION: Takotsubo cardiomyopathy (TCM) is characterized by transient systolic dysfunction resulting in hallmark apical ballooning/hypokinesis without the presence of coronary artery disease.1 The pathophysiology entails extreme stress, which generates a sudden and massive surge of catecholamines which then markedly deranges cardiac contractility.1 One source of the catecholamine surge is pheochromocytoma: a catecholamine secreting tumor of the chromaffin cells.2 We present the case of patient who presents with both TCM and a suspected pheochromocytoma. CASE PRESENTATION:A 56-year-old female with history of both STEMI and NSTEMI presented with chest pain, nausea, vomiting, and lightheadedness. Blood pressure was 197/119 mmHg on admission. Cardiac enzymes were normal, however ECG demonstrated new lateral ST elevations in V4-V6. TTE showed apical and anterolateral akinesis with a markedly reduced EF of 18%. Nitroglycerin infusion was initiated, and patient was transferred emergently for cardiac catheterization. Patent coronary vessels were found, no intervention was performed, and medical management was pursued. Echocardiographic and catheterization findings were consistent with TCM. Further chart review showed multiple similar prior episodes plus a prior CT scan which demonstrated a 2 cm adrenal mass. Given clinical suspicion, workup for pheochromocytoma was initiated. Plasma and spot-urine metanephrines, plus spot-urine normetanephrines and 24-hour urine metanephrines were within normal limits. Plasma normetanephrines, 24-hour urine normetanephrines, epinephrine, norepinephrine, and dopamine were elevated at 731.7 pg/mL, 1538 ug/24 hours, 83 pg/mL, 4213 pg/mL, and 1020 pg/mL respectively.The patient's blood pressure was eventually controlled with oral medications. She was initiated on goal-directed medical therapy for her newly reduced EF and discharged home with endocrinology follow-up.DISCUSSION: Detection of pheochromocytoma is elusive and largely depends on elevated catecholamines in urine or blood samples via 24-hour collection. The difficulty lies in the fact that the secretion is intermittent. Measurement of VMA in urine can be done yet despite a high specificity (95%) there is a low sensitivity (64%).3 Pheochromocytoma can result in mass catecholamine release with systemic manifestations, affecting cardiac contractility.CONCLUSIONS: Our patient presented with TCM from a suspected pheochromocytoma. This diagnosis was reached via a combination of echocardiographic imaging showing apical and anterolateral akinesis, not consistent with any single coronary distribution, a clean coronary catheterization, and several lab panels demonstrating elevated levels of catecholamines/ metanephrines in both the blood and urine.