Postural ventricular tachycardia in patients with pheochromocytoma

Many kinds of cardiac complications have been reported in association with pheochromocytoma, including transient ECG changes, catecholamine-induced myocardial injury and various types of supraventricular or ventricular tachyarrhythmias. We report a case admitted to our hospital for evaluation of ventricular tachycardia. A 45-year old woman entered the cardiology department with the complaint of recurrent palpitation in a position of ante-flexion. Physical examination at a time of admission revealed a regular pulse of 62/min, blood pressure of 100/56 mmHg (sitting). There was no evidence of cardiac enlargement or congestive heart failure. An ambulatory 24 hour ECG showed recurrent ventricular tachycardia short run with wide QRS at the time of ante-flexion. Urea, electrolytes and complete blood count were normal. Serum cardiac enzymes, thyroid function tests and glucose were normal. An echocardiogram confirmed no specific changes, such as left ventricular hypertrophy. 24 hour urine collection confirmed an elevated vanillylmandelic acid (10.4 micrograms/day: normal 2.0-2.8), metanephrine (0.68 micrograms/day: normal 0.04-0.18) and normetanephrine (1.71 micrograms/day: normal 0.1-0.28). Serum catecholamine level showed adrenalin, 0.26 ng/ml: normal less than 0.12) and noradrenaline (3.34 ng/ml: normal 0.1-0.41). These values increased to 1.34 and 24.75 respectively during palpitation attack. Abdominal enhanced computed tomography showed a 3 cm diameter tissue mass in the left adrenal area. Surgical resection of this pheochromocytoma was accomplished uneventfully. It was successfully excised and the patient was discharged in good health two weeks after the operation. Cardiotoxic effects of catecholamines have been well described by many investigators. In our case, tachyarrhythmia was induced without excessive changes of ECG findings. In patients with pheochromocytoma, occurrence of various types of cardiac arrhythmia should be considered.