A Case of Pheochromocytoma Presenting as Ventricular Tachycardia Storm / 대한내과학회지

ABSTRACT

A 35-year-old woman was admitted for recurrent palpitations and headache with cold sweats. No structural abnormality was detected via cardiac imaging studies. A standard 12-lead electrocardiogram (ECG) revealed sustained monomorphic ventricular tachycardia (VT). Propranolol (120 mg/day) was administered; however, the frequency and duration of VT episodes increased rapidly. A 24-hr ambulatory ECG revealed frequent, successive, premature ventricular beats; accelerated idioventricular rhythms; and VTs with various cycle lengths and QRS complex morphologies. ECG findings suggested that the observed ventricular arrhythmias were driven by accelerated automaticity as their main electrophysiological mechanism. Based on clinical manifestations and ECG findings, pheochromocytoma was suspected. Solitary left adrenal pheochromocytoma was diagnosed by endocrine and imaging studies. Instead of propranolol, oral doxazosin (8 mg/day) was administered, and symptoms and VT attacks were successfully suppressed. After surgical resection of the pheochromocytoma, clinical VT was not observed in response to the high-dose isoproterenol provocation test.