How Does Smoking Cause a Heart Attack?

Video Transcript

"Hello. I am Dr. Davis Burns. I am a professor emeritus at the University of California San Diego School of Medicine. Cigarette smoking is one of the major causes of heart attacks in the United States. About a third of the heart attacks that occur in the United States are caused by cigarette smoking. A heart attack occurs when the blood vessels delivering blood and oxygen to the heart muscle become blocked. What then happens is the muscle that is depended on that oxygen and blood delivery dies and you get a scar in the heart and the heart then doesn't work as effectively, because it has lost some of the muscle tissue that it requires in order to pump and to spread blood to the rest of your body. Cigarette smoking causes heart attacks in two principle ways. It increases the buildup of plaque, of the fibril fatty bulging, of the walls of the artery and that narrows then the artery leading to the heart. The second effect of cigarette smoking is that it increases the likelihood that a given part of the artery will clot or will block off or will become ischemic and cause the muscle behind it to then go on to die. So, there are two principle effects. We know that cigarette smoking, even second hand smoke exposure, alters what we call the endothelial function of the blood vessels. That's the function of the inside of the tubes that should provide blood to the rest of the body. That abnormal function increases the likelihood of both formation of atheros crocus, formation of these fatty fibrous plaques in the walls of the arteries and also increases the likelihood that those arteries are going to clot."