A 69-year-old man who had been taking glycyrrhizin for chronic hepatitis had been suffering from watery diarrhea for several weeks. After retrograde urethrography for dysuria, he developed shock and was transferred to our hospital. His blood pressure was 72/44 mmHg and his ECG showed atrial fibrillation, ventricular extrasystoles and non-sustained and then sustained polymorphic ventricular tachycardia(torsade de pointes: TdP). Electrical cardioversion restored sinus rhythm, and the QTc interval was prolonged to 0.62 with a change in T and U waves (slow wave). The serum potassium level was 2.9mEq/l and the serum free calcium level was 0.7mEq/l, but other electrolyte levels were normal. He was diagnosed with TdP occurring in hypopotassemia-induced QT prolongation. He was treated with KCl, dobutamine and dopamine. The TdP attack was diminished within a few days, but the QTc interval returned to 0.42 0n the 20th day. He had no organic heart disease. TdP occurred in the manner of the pause-dependent type, and was accompanied with the prolongation of QTc interval and the fusion of T and U waves. This QT prolongation was produced by hypopotassemia induced by glycyrrhizin-related pseudoaldosteronism and probably hypomagnesemia accompanied by chronic diarrhea. This is the first case, to our knowledge, in which TdP occurred after retrograde urethrography.
