Everyone is told from childhood to "eat right" and "keep fit." As people age, this sage advice takes on a new meaning. LDL cholesterol (aka "bad cholesterol") is a key component in heart and blood vessel problems. High fat diets and lack of exercise are often the starting points to a cycle of disease.
Definition
Carotid arteries are present to the left and right sides of the neck and are the chief pathway of blood enroute to the brain. Stenosis means stiffening, usually achieved through a build up of deposits within a cavity. Carotid stenosis, therefore, is a medical condition referring to an occlusion or semi-occlusion of the carotid artery. The most common cause of carotid stenosis is fat, which adheres to the walls of the arteries and, over time, permits less and less blood to pass. As blood backs up in the arteries, the heart responds by increasing the pressure to push the blood through. With more blood pooling as it awaits its high pressure journey, there is an increased risk of clot formation. Additionally, a piece of the plaque itself make break free. If a clot or fatty particle (embolus) reaches the brain, the result is a stroke.
Stroke
There are essentially two types of strokes. The first type is hemorrhagic (blood induced). This type of stroke is often congenital, meaning that the individual is living on borrowed time due to a flaw in the vessels of the brain. A common manifestation would be a burst brain aneurysm (hyper-distended weak wall of a blood vessel). Other factors that can lead to hemorrhagic stroke are cancer, extensive cocaine use, uncontrolled hypertension or over use of blood thinners. This type of stroke is often fatal. The second type of stroke is the more common ischemic (tissue death from loss of oxygen) stroke, accounting for 80 percent of stroke cases. This is the type of stroke associated with carotid stenosis. In an ischemic stroke, a blood clot is lodged deep inside the vasculature (blood supply) of the brain. Brain tissue that would have been fed by the blocked vessel dies.
Related Conditions
Apart from a stroke, other conditions can arise from carotid stenosis. A common pre-stroke event linked to carotid artery stenosis is a TIA (transient ishemic attack). A TIA is a warning sign that an ischemic stroke may be on the horizon. In this case, the effects are temporary and symptoms are usually resolved in about 24 hours. Victims describe speech problems, either slurring or garbling, loss of movement, weakness, or dexterity to one or more limbs and difficulty in walking. Also, a person may be diagnosed with atherosclerosis, which is the process of narrowing in the carotid artery. In other words, atherosclerosis is the mechanism that causes the stenosis.
Diagnosis
The first step toward a diagnosis may occur right in the physician's office. A simple stethoscope can detect an abnormal sound at the level of the carotid artery. That sound is called a "bruit." If an MD detects a bruit, even in the absence of other symptoms, he may order a carotid ultrasound. An ultrasound is not painful and uses sound technology to trace blood flow through the vessels in the neck and heart. Depending upon the results of an ultrasound, more testing may be indicated. A follow up MRI (magnetic resonance imaging) may be necessary to give an even clearer picture of damaged blood vessels. The most definitive test for measuring blood flow through a narrowed artery is an angiogram. In this test, dye is injected into the patient through a catheter (thin, sterile tube). The dye is picked up by X-ray and presents the clearest diagnostic picture for the physician.
Treatments
Once the diagnosis is made, treatment options can be discussed with the patient. If the level of the blockage is less than 50 percent, medications can be used to lessen the likelihood of an ischemic event. Some of the types prescribed are anti-platelet medications, which prevent platelets from sticking together, easing blood flow. Plavix and aspirin are examples of anti-platelet medications. Anticoagulants are also prescribed, mostly in the acute and symptomatic phases of an early ishemic stroke. Coumadin and heparin are examples of anticoagulants. In those cases where stenosis is 70 percent or more, a surgical approach is usually necessary. The procedure is called a carotid endarectomy. During this operation, the affected vessel is opened and plaque is physically removed by the surgeon. Prognosis for these patients is particularly good postoperatively. Another surgical alternative is carotid angioplasty. This procedure involves the use of a balloon to widen the narrow arterial space and a stent (mesh support) to maintain the patency of the artery.
Prevention
The best measure one can make to prevent atherosclerosis is to limit the amount of LDL cholesterol in the diet. Cholesterol in combination with triglycerides (fats made within the body) are the most significant precursors to heart disease and stroke. Taking control is up to the individual. It is important to read labels on food items and monitor daily calorie intake. A diet too high in carbohydrates will lead to fat production in the body. Exercise has a direct impact on reducing triglyceride levels in the bloodstream, while improving HDL cholesterol ("good" cholesterol) levels.
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