The cardinal sign of pheochromocytoma - hypertension - may not be present in up to 30% of patients despite high circulating levels of catecholamines. We report a case of recurrent hypotension and shock induced by pheochromocytoma.CASE REPORT: A 38-year-old, previously healthy woman presented with severe headache and chest discomfort. The physical examination revealed a drowsy, ill appearing woman. Body temperature of 100.1 °F, blood pressure of 100/60 mm Hg, heart rate of 110 beats per minute, mild neck stiffness, fourth heart sound and rales at lung bases were noted. Laboratory values included creatine kinase, 563 mg/dL; Troponin I 21 ng/mL and leukocyte count, 36,700 cells/μL. After treatment of nausea with metoclopramide patient developed chest pain, hypotension (72/40 mm Hg) and EKG changes (diffuse PR segment depressions and ST elevations in leads V2-3). Echocardiogram showed left ventricular ejection fraction of 30% with circumferential, basal hypokinesis and preserved contractility of the apex. Heart catheterization revealed normal coronary arteries, cardiac index 3.9 L/min/m2 and systemic arteriolar resistance 660 dynes/sec/cm5. The diagnosis of fulminant myopericarditis in the setting of sepsis was made. Patient responded to the therapy with volume resuscitation, dopamine and norepinephrine. Extensive testing to identify infectious pathogen was unrevealing. Patient was discharged in five days on β-blocker and ACE-inhibitor therapy. Follow-up echocardiogram in four weeks was normal.Eight months later patient presented with similar symptoms. However, this time shock was interrupted with several brief episodes of hypertension despite stable dose of vasopressors. Patient complained of palpitation, chest discomfort, muscle cramps and generalized weakness. Low grade fever, leukocytosis, sinus tachycardia, troponin I of 7.9 ng/mL and echocardiographic findings identical with those at the previous admission were noted. MRI of the abdomen revealed 36-mm right adrenal mass. Serum testing confirmed diagnosis of pheochromocytoma (plasma norepinephrine 6766, epinephrine 2296, dopamine 741, and urine metanephrines 8338 nmol/L). She underwent successful surgical resection of the tumor. Area of central necrosis was noted. Follow-up echocardiogram showed normal left ventricular function. She has been asymptomatic for 8 months on no medical therapy.DISCUSSION: Intravascular hypovolemia and decreased myocardial contractility seem to be the key features of shock in patients with pheochromocytoma. Adrenergic diuresis, increased capillary permeability, peripheral β-adrenergic stimulation and attenuated vasoconstrictive response due to the down-regulation of α1 adrenergic receptors result in hypovolemia. Myocarditis is a well-documented complication of any hyperadrenergic state. Dilated, apical hypertrophic, obstructive hypertrophic and non-obstructive hypertrophic cardiomyopathies have been described in patients with pheochromocytoma. This is a first report of a recently recognized, hyperadrenergic state-associated, apical contractility preservation in patient with pheochromocytoma. Imaging with CT, MR or bedside US allows early identification of adrenal mass in patients with pheochromocytoma-induced shock. Serologic confirmation of pheochromocytoma is necessary since clinically silent adrenal incidentalomas are common. Emergent removal of pheochromocytoma in the setting of adrenal shock may be lifesaving.CONCLUSIONS: Pheochromocytoma is a great imitator. In patients with hypotension diagnosis of pheochromocytoma should be considered if they have:1. Other symptoms suggesting pheochromocytoma2. Shock of unclear etiology despite thorough evaluation3. Rapid non-iatrogenic fluctuation of arterial blood pressure4. Myocardial infarction without obstructive coronary stenosis5. Cardiomyopathy, especially with regional wall motion abnormalities that do not match typical coronary artery distributions.6. Relatively mild abdominal trauma causing severe hemodynamic instability7. History of neurofibromatosis, tuberous sclerosis, von Hippel-Lindau syndrome or MEN 2 syndrome8. Family history of pheochromocytoma or MEN 2 syndrome.
B. Schifferdecker, None.