Multifocal ventricular ectopic complexes possibly related to diuretic induced hypokalemia in a woman with the long QT syndrome.

A 40-year-old housewife was observed with chief complaints of syncope and palpitation. The electrocardiogram indicated premature ventricular ectopic complexes of the torsade de pointes. Serum potassium level was low because of thiazide-induced hypokalemia for the treatment of transient hypertension. Even after the disappearance of threatening ventricular arrhythmias and normalization of serum potassium level, prolongation of QT interval was continuously persisted. Thiazide induced hypokalemia might have some roles on producing ventricular ectopic activity in prolonged QT syndrome as shown in our case.