Papavine: The ideal coronary vasodilator for investigating coronary flow reserve? A study of timing, magnitude, reproducibility, and safety of the coronary hyperemic response after intracoronary papaverine

A potent, short‐acting vasodilator that induces a maximal hyperemic response of the coronary vascular bed is needed to determine coronary flow reserve. In 12 patients, we measured coronary sinus blood flow by thermodilution over a period of 2 min during which a bolus of 10 mg papaverine was given into the left main coronary artery. This was repeated after 5 min to assess the reproducibility of the changes. The maximal hyperemic response lasted from 24 until 37 sec after papaverine administration. There was no significant difference between the two consecutive hyperemic responses (Student's t‐test for paired observations). The mean difference between first and second hyperemic responses at 30 sec was 7.0% (SD ± 6.2%). In conclusion, 10 mg of intracoronary papaverine is a short‐lasting and reproducible means of inducing a maximal hyperemic response in the coronary vascular bed and therefore appears to be the ideal agent for investigating coronary flow reserve.