If I Have an Ulcer on My Foot, Why Do I Need an EKG?

The twisting, burning pain in her right calf started up again as Ms. J hurried through the clinic parking lot for her doctor appointment. She stopped for a minute, leaning against a car to wait for the pain to ease. Lately the pain had been really slowing her down and was taking longer to go away. Ms. J just wished it to go away for good. Her primary care doctor told her that quitting smoking was essential in helping her circulation problems, and he also referred her to a vascular specialist.

The nurse checked Ms. J's blood pressure and weight and looked over her paperwork. Then she had Ms. J take off her shoes and socks and examined her feet. Ms. J had never noticed how purple her right foot looked when she was sitting down or that little blister on the end of her big toe. Then the nurse checked the blood pressure in her legs. No one had ever done that before!

The nurse explained that people have blood pressure in their legs as well as their arms and that an abnormal reading can be caused by a clogged artery slowing the flow of blood down the leg. Ms. J thought that made some sense. The nurse then told Ms. J that she would have an EKG before the doctor came in.

"But I'm here for my leg pain, not any heart problems," protested Ms. J. The nurse explained that the EKG is a screening test for the heart, just like the arm and leg pressure readings she had just done, or just like a blood test. That made sense to Ms. J. The pain in her leg was bad enough that she certainly would not want that pain occurring in her heart too!

Peripheral Arterial Disease and Coronary Artery Disease: What Is the Connection?
The nurse who examined Ms. J knew that the symptoms the patient was having were enough to check her for both peripheral arterial disease (PAD) and coronary artery disease (CAD). PAD occurs when one or more of the arteries that supply fresh blood to the muscles of the legs are narrowed or completely blocked by plaque.

Plaque is a fat-like substance composed of macrophages (a type of scavenger blood cell), cholesterol components, fibrin (a sticky protein), calcium, and other proteins. Small areas of plaque lodge in the arterial walls, usually in places where the artery bends, branches, or is stressed from pressure or injury. Over time, plaque areas can accumulate and become large enough to slow down or even stop the flow of fresh blood to the muscles in the leg below the blockage. When there isn't enough blood flow to the muscles to supply them with oxygen or sufficient nutrients to keep up with the needs of the muscles' activity (such as walking), pain such as cramping or burning occurs. The pain goes away when the activity is stopped because the muscles are resting and the supply of blood is able to keep up with the needs of the muscle. This is called intermittent claudication or simply claudication. As the flow of blood becomes less and the areas of blockage become larger, the muscles are deprived of nutrients and oxygen even at rest. Pain that interferes with sleep and requires medical attention is called rest pain. Attempting to sleep sitting up or with the leg dangling over the side of the bed may relieve some of the pain because gravity helps pull the blood through the arteries. Areas on the foot, especially the toes, are lacking in blood supply so much that a small injury does not heal, but becomes larger until it is a visible sore or ulcer. Bacteria can lodge in the sore and the body can't fight it off because there is not enough blood to that area to supply the germ-fighting blood cells that are needed.

While not all people with PAD have these "classic" symptoms, if you do exhibit these or other symptoms it is important to have your doctor test you for PAD.

CAD occurs when one or more of the arteries that supply fresh blood to the heart muscle become narrowed or completely blocked by plaque. Plaque in the arteries of the heart is composed of substances similar to the plaque in the arteries of the leg and develops in a similar way. When the heart muscle's need for oxygen and nutrients from the blood is greater than the flow of blood getting through the blocked area of the artery, pain occurs. The pain is commonly described as a squeezing or pressure sensation in the middle of the chest, also known as angina. There may be other symptoms as well, such as shortness of breath, pain in the arm or jaw, or extreme weakness. Angina occurs with activity such as carrying a heavy object or going up a flight of stairs, and then goes away with resting. As the blockage increases in size, the angina occurs with normal activity, and sometimes even at rest. This progression of symptoms is similar to the progression of symptoms for PAD. Although PAD and CAD are similar, there are two important differences in the heart. One is that the heart muscle is always moving (beating) and does not rest in the same manner as leg muscles do. The second is that the heart arteries are smaller and fewer in number than the leg arteries, so blockages in the heart can develop at a different rate.

Development of plaque in the arteries of the leg (PAD) or the heart (CAD) is affected by the same things: age, high blood cholesterol from diet or inheritance, smoking, diabetes, high blood pressure, and lack of exercise. Other arteries can be affected as well, especially the carotid (neck) arteries that supply blood to the brain. Because all the arteries are interconnected, with the heart at the hub, arterial disease can develop in more than one place in the body at a time. Since the heart is the central pump where blood is circulated, it is important to ensure that it is working properly and to detect potential problems before damage is done, even before symptoms occur. People who have PAD have a 30% greater chance of also having CAD. Doctors who treat PAD will also be screening for CAD. Having an EKG is the first step in this evaluation. A stress test is sometimes done after the PAD symptoms have been relieved or before planned surgery for PAD. Lifestyle changes such as quitting smoking, walking, diet, and medical treatment of high blood pressure, diabetes, and high cholesterol should take place in all patients with PAD even if there is no evidence of active CAD.

Ms. J did in fact have both PAD and CAD. She is one of the nearly 12 million people in the United States who have PAD and the more than 15 million people in the United States with CAD.

About the Author: Barbara Parness, RN, CCRN, MS, APRNCNS. Barbara is a clinical nurse specialist with a cardiovascular group of 18 physicians based in a northwest suburban area of Chicago.