Coronary Artery Disease
Normal coronary arteries are smooth and elastic. Through a process known as atherosclerosis, fatty deposits can build up narrowing the inside of the arteries. When fatty matter hardens, it is called plaque. Plaque can damage the lining of the arteries and blood clots can form, allowing less blood to flow through the arteries.
Angina
The most common symptom of coronary artery disease is angina pectoris. Angina signals that the need for oxygen by the heart muscle has exceeded its supply. The chest discomfort may be described as pressure or tightness, or as a feeling of constriction. Often, people indicate that the feeling is described as numbness, heaviness, or a dull aching or burning sensation. Frequently, angina is mistaken for indigestion. The discomfort associated with angina may be felt in the chest beneath the breastbone and may radiate to the shoulders and arms, more commonly, the left. The discomfort may also be felt in the neck or jaw. Angina may be precipitated by exercise, stress, exposure to the cold or after eating. As coronary artery disease progresses, angina may even occur at rest. The symptoms of angina usually last only a few minutes and are frequently relieved by rest or by placing a nitroglycerin tablet under the tongue.Heart Attack
A heart attack or myocardial infraction (MI) occurs when blood flow through a coronary artery becomes completely blocked. Frequently, a blood clot obstructs the artery at a site where there is narrowing from atherosclerosis. This results in permanent damage to the heart muscle, supplied by the coronary artery. The discomfort associated with a heart attach is often more severe than that of angina and may last longer. It may not be relieved by NTG, or only temporarily relieved, and is frequently associated with nausea, shortness of breath or sweating.Diagnosis of Coronary Artery Disease
Diagnosis begins with a review of an individual's history and assessment of symptoms, as well as a physical exam. An electrocardiogram, or ECG, involves placing electrodes on the chest. The electrodes are attached to a machine that records wave forms generated by the electrical activity of the heart. Previous heart damage can usually be detected by an ECG. It is important to understand however, that a normal ECG does not exclude the possibility of coronary artery disease. An echo, or echocardiogram, is a test that uses sound waves to visualize the movement of the heart on a video screen. It is non-invasive and involves having a technician put special jelly on the probe and move the probe over the chest. These tests may be ordered to determine how well the heart contracts, the function of the heart valves, or if there is a blood clot inside the heart.An exercise stress test, sometimes called a treadmill test, may be ordered to evaluate how well a heart functions under stress. It can be used to identify reduced blood supply to the heart muscle. The test involves attaching an individual to a heart monitor and walking on a treadmill while the heart rhythm and blood pressure are recorded. The stress test may be combined with a scan of the heart to provide even more information for the physician. A cardiac catheterization, or coronary angiogram, is a test in which a catheter is inserted into an artery in the leg under a local anesthetic. A tranquilizing medication is usually prescribed before the test to assist with relaxation. Dye is injected and special x-rays are taken to identify blockages in the coronary arteries. Pictures are also taken of the heart during contraction to see how effectively the heart muscle is pumping. The procedure usually takes about an hour and bed rest for several hours after the procedure is usually necessary.
Treatment of Coronary Artery Disease
There are three general categories of treatment option. Medical treatment may include a low sodium, low cholesterol diet, supervised exercise and the use of a variety of drugs. When medical therapy is not successful, or when the disease progresses, further evaluation may be recommended and other therapy suggested.Interventional procedures, performed by cardiologists, include ballon angioplasty (percutaneous transluminal coronary angioplasty, or PTCA). During this procedure, a catheter is guided into the narrowed coronary artery, the balloon is inflated, compressing the plague material against the artery wall. The larger opening in the artery allows for improved blood flow. Other coronary interventions include the use of stents, metal devices inserted through a special catheter, which can be placed after balloon angioplasty at the narrowed site. The stent helps to prevent the area from becoming narrowed again. Coronary atherectomy is similar to balloon angioplasty, except that the catheter has a rotational device designed to shave thin layers off the plague from the coronary artery wall. The thin pieces of plage are then collected in a section of the catheter and removed with the catheter. Sometimes, depending on the number and the location of the blockages, interventional procedures may not be appropriate and surgery may be recommended.
Coronary artery bypass surgery is also called CABG, or “cabbage”. During the procedure, a leg vein (saphenous vein) or an artery from the chest (internal mammary artery) are used to bypass one or more blockages in the coronary arteries. When the internal mammary artery is used, it is left attached as it comes off a branch of the aorta, and the other end sewn to the coronary artery beyond the blockage. When a leg bein is used, one end is attached to the aorta, and the other end is sewn to the coronary artery below the blockage. Sometimes an artery is removed from the arm and used as a graft, sewn to the aorta with the other end attached to the coronary artery beyond the blockage.
Studies have indicated that, in genera, arterial grafts usually will stay open longer than veins. Many factors influence the surgeon's decision regarding which types of grafts will be used. These include, but are not limited to, the number of blockages, locations of blockages, and the size of the coronary arteries. Other factors to b e considered are the age and general health of the patient. Newer techniques utilized by Vlaley Cardiac Surgery, include a minimally invasive approach, in which the procedure is performed through a smaller, more cosmetically pleasing incision. Once again, many factors are involved in selecting appropriate candidates, including the number and location of coronary blockages. Always of paramount importance, in a safe and effective surgical outcome. Another newer technique employed by Valley Cardiac Surgery, involves performing coronary artery bypass surgery on selected patients without the use of cardiopulmonary bypass. Special stabilizing devices are utilized to allow the procedure to be done while the heart is beating.
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