Papaverine-induced QT interval prolongation and ventricular fibrillation in a patient with a history of drug-induced QT prolongation.

A 64-year-old woman underwent a coronary flow reserve evaluation using intracoronary-administered papaverine into the left anterior descending artery. Her baseline electrocardiogram (ECG) was normal, but toward the end of papaverine administration, the QTU intervals were excessively prolonged and torsade de pointes occurred, leading to ventricular fibrillation. Ten months previously, the patient's ECG showed mildly prolonged QTc (480 ms(1/2)), which normalized after the cessation of bepridil. This case report suggests that a history of drug-induced QT prolongation can be a risk factor for papaverine-induced fatal ventricular arrhythmia.