The Assessment of Oxidative Stress Markers and the Development of Atrial Fibrillation After Cardiac Surgery

The purpose of the investigators study is to investigate the correlation between naturally occurring chemicals, called reactive oxygen species (ROS), in the blood of human patients and the development of an abnormal heart rhythm, known as atrial fibrillation (AF). The development of atrial fibrillation is associated with increased medical problems like stroke. Many factors seem to cause the development of AF, and this rhythm occurs frequently after open heart surgery. When patients develop AF after cardiac surgery they are at increased risk for cognitive changes, infections, the development of kidney failure, and increased length of hospitalization. ROS are chemicals in blood and tissues that tend to cause microscopic blood vessel and heart damage. These chemicals occur naturally as the result of chemical reactions that occur in states of stress and inflammation, like tissue trauma and as the result of smoking. Patients who undergo cardiac surgery may have higher levels of ROS because of their underlying medical conditions. In addition, the organized tissue trauma that occurs in the setting of surgery may serve to increase ROS levels further. In turn, the higher ROS levels may put patients at even higher risk for the development of AF. The investigators believe that increased levels of ROS may help potentiate a patient's development of AF. Accordingly the investigators aim to measure ROS levels before and after surgery to see if there are particular levels that predict the development of this abnormal heart rhythm. By developing a better knowledge of the relationship between ROS and AF, the investigators hope to better understand another possible method of detecting patients who are at the highest risk of developing AF before it occurs after surgery. If these patients are better identified, this may eventually lead to medical treatment to prevent AF; and hopefully this will result in a decrease of the malicious effects that result from developing this abnormal heart rhythm.