Postischemic Hemodynamic Changes after Piroximone Administration in Isolated Rabbit Heart

Abstract

In an experimental study on 22 adult Elco rabbits, hemodynamic parameters were investigated using a working heart model. The study group (10 rabbit hearts) received 1 mg/kg i.v. of the phosphodiesterase inhibitor piroximone 15 min before thoracotomy. 12 untreated rabbit hearts served as a control group. Hemodynamic parameters were measured before and after 60 min of hypothermic ischemia. The pre-ischemic period showed no significant differences between the two groups, except the higher levels of coronary flow in the piroximone group. The postischemic period showed significant increases in heart rate, coronary flow, aortic flow and cardiac output in the piroximone group in comparison to the control group. These results indicate as a main effect the positive influence of piroximone on coronary flow, given as a single shot 15 min preoperatively. This study provides evidence of the vasodilative properties on the coronary arteries beside the documented effects on the periphery. Therefore, piroximone represents an alternative tool in weaning from the cardiopulmonary bypass.