Polymorphous ventricular tachycardia: a side effect of intracoronary papaverine.

Polymorphous ventricular tachycardia occurred in 1.3% of patients (5 of 391) who received intracoronary papaverine over a 47 month period. The arrhythmia lasted less than 1 min in all five patients, converting spontaneously in four and requiring electrical cardioversion in one. Ventricular tachycardia occurred in 4.4% of women (4 of 90) and 0.3% of men (1 of 301) (p less than 0.0025). Only one of the patients with ventricular tachycardia had coronary artery disease. To determine whether other clinical or procedural factors predispose patients to this side effect of papaverine, these 5 patients were compared with 25 control patients who were matched for gender and extent of coronary artery disease. The following variables were analyzed: age, baseline serum potassium and calcium levels, left ventricular ejection fraction, baseline heart rate, mean arterial pressure, corrected QT interval, the change in corrected QT interval produced by papaverine and the maximal dose of the drug per kilogram of body weight. Of these variables, only baseline heart rate differed significantly in the two groups of patients. Thus, polymorphous ventricular tachycardia is an infrequent, but important, side effect of papaverine that is usually self-limited. Women with a relatively slow heart rate appear to be predisposed to this side effect.