A Case Report of Myocardial Infarction Complicated With Blood Pressure Fluctuations Caused by Pheochromocytoma.

Pheochromocytoma typically presents with sustained or paroxysmal hypertension, but initial manifestation as acute non-ST-segment elevation myocardial infarction (NSTEMI) is rare. Peri-procedural hemodynamic fluctuations are often dramatic, making diagnosis and management challenging. We report a 51-year-old male admitted with chest tightness for 17 days. Elevated troponin and coronary angiography showing multivessel disease with total occlusion of the mid-left anterior descending artery (LAD) led to a preliminary diagnosis of NSTEMI. During percutaneous coronary intervention, blood pressure surged to 240/130 mmHg; intravenous nitroprusside caused an instantaneous drop to 95/55 mmHg, with rapid rebound to >200 mmHg upon withdrawal, showing no clear temporal relationship with drug administration. Postoperatively, large rapid blood pressure oscillations persisted, associated with postural changes but without patient discomfort. Workup revealed markedly elevated plasma catecholamines: dopamine 77.58 pg/mL (normal 0-20), normetanephrine 1881.63 pg/mL (0-145), and norepinephrine 5,724.04 pg/mL (217-1,109). CT and PET-CT identified a left retroperitoneal mass (59×34×44 mm, SUVmax 14.6), suggestive of pheochromocytoma. Surgical resection was performed, and histopathology with immunohistochemistry confirmed the diagnosis. Postoperatively, the patient required no antihypertensive medications and blood pressure remained stable. This case illustrates a rare pheochromocytoma presentation as secondary hypertension manifesting as acute myocardial infarction, characterized by extreme peri-procedural hemodynamic instability during PCI and an "all-or-none" response to conventional antihypertensive therapy, ultimately cured by surgical resection.