Co-enzyme Q10 is a vitamin-like substance which is synthesized in the body and can be found in some food. The mitochondrias are the energy generators of the cells and the highest proportion of Q10 is in the cells that do the most work, notably the myocardium and the liver.
In congestive heart failure, the heart muscles become weak resulting in poor circulation and shortness of breath. Patients with CHF have significantly lower levels of CoQ10 in heart muscle cells than healthy people.