Pheochromocytoma is an unusual cause of hypertension. It accounts for only 0.1% of the hypertension found in adults¹⁾. Pheochromocytoma in pregnancy is extremely rare, and only about 200 cases have been reported in literature reviews. This disorder carries a high risk of maternal and fetal mortality if undiagnosed before delivery²⁾. The various clinical manifestations of hypertension could resemble those of toxemia in pregnancy, preeclampsia, a ruptured uterus and shock immediately after delivery²⁾. Therefore, in the case of fluctuating hypertension with characteristic symptoms during pregnancy, the physician should suspect pheochromocytoma. However, antepartum diagnosis is missed in about two-thirds of the cases. In many patients, the symptoms of pheochromocytoma are first-manifested during delivery.

Catecholamine induced cardiomyopathy has been reported in some of the literature^3,4). It is very important to manage such a patient with aggressive and appropriate medical therapy because the initial management is closely related to the prognosis⁴⁾. In world literature, only about five cases of pheochromocytoma induced cardiomyopathy in pregnancy have been reported. In Korea, no such case has been reported. Here, we report the case of a 34-year-old pregnant woman with pheochromocytoma who developed catecholamine induced cardiomyopathy after delivery and made a dramatic recovery through proper medical management.

A 34-year-old pregnant woman underwent a normal vaginal delivery. She had no previous history of hypertension and there was no evidence of toxemia in pregnancy or preeclampsia in the prenatal examination. At the terminal period of pregnancy, the patient showed mild hypertension, which was well controlled by nifedipine. Immediately after delivery, her blood pressure rose rapidly and showed marked fluctuation (140/90~210/90 mmHg). The pulse rate increased from 70/min to 150/min. The patient complained of a severe headache, palpitations, chest discomfort, dyspnea and postural dizziness. The blood pressure and pulse rate could not be controlled by nifedipine and her symptoms worsened. Her breathing sounds were normal and the heart sound was regular; there was no murmur. The abdominal mass was not palpated. No periumbilical bruit was heard. Blood tests and simple chest X-ray showed no abnormal findings. Serum CK/CK-MB/LDH levels were 268/23/607 U/L. There was no interval change in serum CK/CK-MB/LDH levels in serial follow-up. The electrocardiograph showed sinus tachycardia, left ventricular hypertrophy and a non-specific ST change in the precordial leads (Fig. 1). In the transthoracic echocardiograph, left ventricular contraction was depressed (ejection fraction = 25%) and akinesia of the septal, anterior and inferior walls was noted (Fig. 2). In a 24-hour urine collection, the total metanephrine level was 15.4 mg/day (normal value; 0~1.2 mg/day), the vanilmandelic acid (VMA) level was 26.6 mg/day (normal value; 2.0~10 mg/day), the epinephrine level was 1682 ug/day (normal value; 0~40 ug/day) and the norepinephrine was 3111 ug/day (normal value; 0~80 ug/day). The serum norepinephrine and epinephrine levels were 4791 pg/ml (normal value; 100~410 pg/ml) and 1657 pg/ml (normal value; ä120 pg/ml), respectively. The abdominal computerized tomography (CT) showed a well-enhanced oval-shaped mass in the right adrenal gland (4.5cm × 3.6cm) (Fig. 3). The patient was diagnosed with pheochromocytoma on the 2 day after delivery. Cardiomyopathy induced by increased catecholamine was also diagnosed because of the abnormal echocardiographic findings.

Phenoxybenzamine was used to control the hypertension and metoprolol was added after the phenoxybenzamine use. Enalapril was prescribed to treat the myocardial damage. After medication, the patient’s blood pressure decreased to the normal range and her symptoms disappeared. Serial transthoracic echocardiography was performed on the second day after the medical management. It revealed a dramatic increase in the left ventricular ejection fraction (to 49%) and complete resolution of the regional wall motion abnormalities (Fig. 2). In the early treatment period, the patient complained of postural dizziness and there was evidence of postural hypotension. The dosage of phenoxybenzamine was reduced in order to prevent the development of such symptoms. A right adrenalectomy was performed after 20 days of medical management. The mass was 5×5 cm in size and there was no evidence of malignancy. After the surgery, the patient’s blood pressure was well controlled by metoprolol and enalapril without phenoxybenzamine. In the 24-hour urine collection after the right adrenalectomy, the total metanephrine level decreased to 0.5 mg/day and the VMA level was 4.5 mg/day. The baby was healthy without neonatal growth retardation, and the patient discharged without complication.

The prognosis for pheochromocytoma in pregnancy is greatly influenced by antenatal diagnosis. The diagnosis of pheochromocytoma in pregnancy is not different from that in non-pregnant women. Clinical suspicion is the most important factor for diagnosis. Consequently, the physician should include pheochromocytoma in the differential diagnosis of pregnancy-associated hypertension.

Our case was complicated with cardiomyopathy. Cardiomyopathy induced by pheochromocytoma in pregnancy may worsen the prognosis. Severe left ventricular dysfunction in this patient showed a marked improvement after the medical management.