It's already known that there is a connection between erectile dysfunction and coronary disease. The risk factors are the same for both, and thus, ED can be a marker for coronary disease. Normal erections are caused when nitric oxide is made, but with endothelial dysfunction, the body doesn't make enough of it, causing the erectile dysfunction. Normally, Viagra prevents the breakdown of the little nitric oxide that is there, so that there is enough of it for an erection to occur.

Howard Herrmann