Heart attacks comprise one of the main causes of death in the USA. A main adverse influence in the heart is arrhythmia involving disruption of cardiac electrical function. Another category of injury is necrosis. Mounting evidence implicates electron transfer (ET), reactive oxygen species (ROS) and oxidative stress (OS) as important factors in cardiovascular diseases. In the generation of ROS, many in vivo enzymes are involved, in addition to exogenous agents. Less attention has been paid to ET functions as the source of ROS. Participation of OS is supported by beneficial effects of antioxidants, but not in all cases. It should be recognized that reaction mechanism is often multifacete
