A 47-year-old patient presented with syncope and recurrent episodes of poly
morphic ventricular tachycardia. She had evidence of prolonged QT interval
by ECG and had been taking cesium as a dietary supplement. Correction of th
e hypokalemia and discontinuation of the cesium resulted in normalization o
f the QT interval during follow-up with no further recurrence of ventricula
r arrhythmias. The use of this drug is potentially hazardous as it may indu
ce fatal ventricular arrhythmias.