Brugada syndrome with ventricular tachycardia and fibrillation related to hypokalemia.

A 60-year-old man with asymptomatic Brugada syndrome and neither a history of syncope nor family history of sudden death was admitted because of bronchial asthma. Serum potassium concentration was 3.8 mmol/L on admission, and decreased to 3.1 mmol/L on the 6th day, probably as a side effect of steroid therapy. The patient was found unconscious on the 7th day, and his serum potassium concentration was 3.4 mmol/L immediately after the episode. On the 8th day, the patient was again found unconscious, and polymorphic ventricular tachycardia and fibrillation (VT/VF) was documented on electrocardiographic (ECG) monitoring. The coved type of ST-segment elevation in leads V(1-3) was observed on the ECG after spontaneous recovery of sinus rhythm, and VT/VF associated with Brugada syndrome was diagnosed. The serum potassium concentration decreased to 2.9 mmol/L immediately after the episode, but QT prolongation was not observed during the clinical course. After the correcting the serum potassium concentration, there was no further recurrence of the malignant ventricular arrhythmia and syncope. An implantable cardioverter defibrillator was inserted to prevent sudden death. Hypokalemia that does not induce QT prolongation may contribute to the occurrence of VT/VF in Brugada syndrome.