QT prolongation and possibility of ventricular arrhythmias after intracoronary papaverine.

The incidence of ventricular arrhythmias following the intracoronary injection of papaverine was assessed. A 3F coronary Doppler catheter was placed in the proximal left anterior descending artery and 6-12 mg of papaverine was injected into the left coronary artery in 42 patients. After intracoronary papaverine, the corrected QT interval on the electrocardiogram was prolonged from 0.43 +/- 0.03 to 0.49 +/- 0.07 s (p < 0.001). Occasional premature beats were observed in 2 patients (4.5%) with dilated cardiomyopathy. In 1 patient (2.3%) with 99% stenosis of the left anterior descending artery, polymorphous ventricular tachycardia with marked QT prolongation occurred. This patient also had hypokalemia (2.5 mEq/l) due to primary aldosteronism. In conclusion, careful use of intracoronary papaverine is necessary because of the risk of occasional serious ventricular arrhythmias.