Experimental study of the relationship between perfluoro-octyl bromide emulsion and norepinephrine release in reperfusion arrhythmia: Isolated guinea pig heart model

Background: Perfluoro-octyl bromide (PFOB), one of the perfluorochemical oxygen transporters, improved postischemic cardiac dysfunctions. Also norepinephrine (NE) is one of the important inducible factors on reperfusion arrhythmias (ventricular fibrillation [VF]). We used these methods to evaluate the relationship between PFOB emulsion and NE release on reperfusion arrhythmias. Materials and Methods: The perfusion of isolated guinea pig hearts was employed: each of four groups of 6-7 hearts were used with Krebs-Henseleit solution (KHS) as control, and KHS with 5%, 15%, or 30% PFOB emulsion. The hearts were perfused in a constant pressure Langendorff model, stabilized for 30 min, followed by 30 min preischemia, then 30 min ischemia and 45 min reperfusion at normothermia. Results: PFOB emulsion dose-dependently limited VF and inhibited NE release in reperfusion. Only 30% PFOB emulsion showed the significant improvement of VF (p = 0.05). In hemodynamic parameters, only 5% PFOB emulsion showed a significant decrease in reperfusion, but there was no difference in coronary flow rate (CFR). No differences among the four groups were demonstrated in cardiac oxygen metabolic parameters. Conclusions: It was most likely that a high concentration of PFOB emulsion attenuated reperfusion arrhythmia by decreasing NE release. (Ann Thorac Cardiovasc Surg 2008; 14: 363-368)