Case Presentation: A 46-year-old man with history of hypertension and no prior history of heart failure presented with acute hypoxic respiratory failure and was subsequently intubated. Chest imaging revealed pulmonary edema and echocardiography showed an ejection fraction (EF) of 10-15% with severe global left ventricular systolic dysfunction. Patient’s respiratory status improved after two doses of Furosemide 40 mg and he was subsequently extubated. For the next few days, this patient had episodic hypertensive spells up to 260/130, along with pulsatile headache, palpitations, and diaphoresis, requiring intermittent Nicardipine infusion which normalized the blood pressure. Repeat echocardiography showed an EF of 65% with preserved left ventricular systolic function. This raised suspicion for catecholamine-secreting tumor. Initial biochemical tests showed elevated serum normetanephrine 1102 (0-145 pg/mL), elevated 24-hour urine norepinephrine and dopamine at 3010 (0-135 ug/24 hr) and 727 (0-510 ug/24 hr), respectively. Imaging of the abdomen and pelvis showed a 5.2 cm left para-aortic mass. This patient was discharged with blood pressure range from 110-150/80-95 on Phenoxybenzamine, Hydralazine and Labetalol and underwent resection of the tumor one month later with pathology showing paraganglioma.
Discussion: Paraganglioma, similar to pheochromocytoma, is a rare neuroendocrine tumor consists of cells that arise from extra-adrenal autonomic paraganglia which have the ability to secrete catecholamines. The classic triad of symptoms consists of episodic headache, sweating and tachycardia. Interestingly, this patient initially presented with respiratory failure. This could be due to transient cardiomyopathy from catecholamine-mediated myocardial dysfunction. When left ventricle has severe global hypokinesis, the decreased forward flow leads to the activation of the renin-angiotensin-aldosterone and sympathetic nervous systems. This subsequently causes compensatory renal sodium and water retention, resulting in pulmonary edema. When this patient’s blood pressure was better controlled, repeat echocardiography showed normalized ejection fraction with recovery of the kinetics of left ventricle. This quick resolution of cardiomyopathy along with episodic hypertension crisis warrants workup for catecholamine-secreting tumor. Once the diagnosis is confirmed with biochemical testing and imaging, adequate blood pressure control with an alpha-blocking agent, followed by a beta-adrenergic agent should be achieved prior to surgical resection.
Conclusions: Respiratory distress can be a presenting symptom in pheochromocytoma/paraganglioma. This could be due to transient catecholamine-mediated cardiomyopathy that can resolve with stabilization of blood pressure. Acute presentation of decompensated heart failure with a hypertensive emergency should raise suspicion for catecholamine-releasing tumor, as early diagnosis and resection of the tumor are essential to prevent cardiac or neurological complications.