Disturbances in the heart rhythm – called arrhythmias – are common in the early phase of reperfusion after myocardial infarctions. Free radicals play a key role in such arrhythmias, mostly based on results from small rodents, and the effect of antioxidant therapy remains debated.
Together with other colleagues at IEMR, PhD student Marie Haugsten Hansen and Postdoctoral Fellow Mani Sadredini aimed to provide evidence for oxidative stress in the early phase of reperfusion in a large animal model, and to test the effect of antioxidant therapy with N-Acetylcysteine (NAC) on reperfusion arrhythmias. Myocardial infarction was induced during open heart surgery by Morten Eriksen, and the pigs were randomized to receive either NAC or placebo.
The main findings confirmed an increase in oxidative stress during the early reperfusion phase, and that this was higher in the infarct zone compared to the bordering and remote zones. However, treatment with NAC did not reduce oxidative stress, nor protect against reperfusion arrhythmias. The results illustrate the importance of pigs and large animals for validation of concepts identified in rodents. More insight into the role of free radicals in reperfusion arrhythmias is needed for antioxidant therapy to be considered as a treatment option.