Background: Papaverine is useful for evaluating the functional status of a coronary artery, but it may provoke malignant ventricular arrhythmia (VA). The aim of this study was to investigate the incidence, and clinical and ECG characteristics of patients with papaverine-induced VAs. METHODS AND RESULTS: The 182 consecutive patients underwent fractional flow reserve (FFR) measurement of 277 lesions. FFR was determined after intracoronary papaverine administration by standard procedures. The clinical and ECG characteristics were compared between patients with and without ventricular tachycardia (VT: ≥3 successive premature ventricular beats (PVBs), or ventricular fibrillation (VF)). After papaverine administration, the QTc interval, QTUc interval, and T-peak to U-end interval were prolonged significantly. Single PVBs on the T-wave or U-wave type developed in 29 patients (15.9%). Polymorphic VT (torsade de pointes) occurred in 5 patients (2.8%), and of those, VF developed in 3 patients (1.7%). No clinical and baseline ECG parameters were predictors for VT or VF except for sex and administration of papaverine into the left coronary artery. Excessive prolongation of QT (or QTU), T-peak to U-end intervals and giant T-U waves were found immediately prior to the ventricular tachyarrhythmias (VTAs), which were unpredictable from the baseline data.
Conclusions: Intracoronary administration of papaverine induced fatal VTAs, although the incidence is rare. Excessive prolongation of the QT (and QTU) interval appeared prior to VTAs; however, they were unpredictable.