Atherosclerosis

Atherosclerosis starts in the arteries as early as childhood and is a slow, progressive disease. The precise causes that lead to atherosclerosis are unknown. But, damage or injury to the inner layer of an artery may initiate the process of atherosclerosis. The damage may be caused by:

• High blood pressure
• High cholesterol, often from getting too much cholesterol or saturated fats in your diet
• Smoking and other sources of nicotine
• Diabetes

Damage to the inner arterial walls leads to build up of blood cells and other substances at the injury site and further damaging the inner lining of the artery. With passage of time, fatty deposits (plaques) made of cholesterol and other cellular waste products also build up at the injury site. The hardening and narrowing of your arteries is caused by these plaques. Blocked arteries lead to insufficient blood supply to the organs and tissues connected to themleading improper function of these arteries.

Further, these plaques may break off and enter bloodstream. Additionally, the smooth lining of a plaque may rupture, spilling cholesterol and other substances into your bloodstream. As a result of these changes a blood clot forms which can completely block the blood flow to a specific part of your body. If this happens in arteries of heart, it leads to a heart attack. It is also noteworthy that a blood clot can travel to arteries of other parts of your body and block (partially or totally) blood flow to another organ.

The process of atherosclerosis is a gradual one. Mild atherosclerosis usually doesn’t have any symptoms. The symptoms of atherosclerosis don’t develop until an artery is so narrowed or clogged that it can’t supply adequate blood to your organs and tissues. In extreme circumstances, a blood clot blocks blood flow completely, or even breaks apart and can trigger a heart attack or stroke.

Moderate to severe atherosclerosis can lead to symptoms dependingupon which arteries are affected. For example:

• Atherosclerosis in your heart arteries can lead to symptoms such as chest pain or pressure (angina).
• Atherosclerosis in the arteries leading to your brain can lead to signs and symptoms such as sudden numbness or weakness in your arms or legs, difficulty speaking or slurred speech, or drooping muscles in your face. All these symptoms are temporary and point towards a diagnosis of a transient ischemic attack (TIA) — which, if left untreated — may progress to a stroke.
• Atherosclerosis in the arteries in your arms and legs can lead to symptoms of peripheral artery disease, such as leg pain when walking (intermittent claudication).
• Atherosclerosis in the arteries leading to your kidneys can lead to development of high blood pressure or kidney failure.
• Atherosclerosis in the arteries leading to your genitals can cause difficulties in having sexual intercourse. Atherosclerosis is an important cause of erectile dysfunction in men. In women, high blood pressure can reduce blood flow to the vagina, making sexual intercourse less pleasurable.

If somebody feels he/she has above symptoms pointing towards atherosclerosis, it is important to meet a doctor. One should also be vigilant about early symptoms of inadequate blood flow, such as chest pain (angina), leg pain or numbness. The patients must understand that early diagnosis and treatment can stop atherosclerosis from worsening and prevent a heart attack, stroke or another medical emergency.

During a physical examination, the doctor may find signs of narrowed, enlarged or hardened arteries. These include:

• Weakened or absent pulse below the narrowed area of your artery
• Reduced blood pressure in an affected limb
• Hearing whooshing sounds (bruits) over your arteries with a stethoscope
• Noticing a pulsating bulge (aneurysm) in your abdomen or behind your knee
• Delayed or poor wound healing in the area where your blood flow is restricted

Physical examination signs along with high suspicion could lead to your doctor suggesting one or more diagnostic tests, including:

• Blood tests.Blood testing in the laboratory can detect increased levels of cholesterol and blood sugar that may increase the risk of atherosclerosis. These tests are performed empty stomach and you’ll need to go without eating or drinking anything but water for nine to 12 hours before your blood test.
• Doppler ultrasound. Your blood pressure may be measured at various points along your arm or leg by the doctor using a special ultrasound device (Doppler ultrasound). Taking these readings can help your doctor gauge the degree of any blockages, as well as the speed of blood flow in your arteries.
• Ankle-brachial index.Atherosclerosis in the arteries in your legs and feet can be detected by this test. Your doctor may compare the blood pressure in your ankle with the blood pressure in your arm. This is known as the ankle-brachial index. A difference in readings out of the normal range may indicate peripheral vascular disease, which is usually caused by atherosclerosis.
• Electrocardiogram (ECG).It is an electrical recording of the signals as they travel through your heart. Evidence of a previous heart attack can be revealed by an ECG. If the signs and symptoms of your atherosclerosis is more evident during exercise, your doctor may ask you to walk on a treadmill or ride a stationary bike during an ECG.
• Stress test.Stress test is also an exercise stress test. IT is used to gather information about how well your heart works during physical activity. By doing exercise on bike or treadmill your heart pump harder and faster than it does during most daily activities. Testing of the heart during and after exercise can reveal problems within your heart that might not be noticeable otherwise. The procedure usually involves walking on a treadmill or riding a stationary bike while your heart rhythm and blood pressure and breathing are monitored. In some types of stress tests, pictures will be taken of your heart, such as during a stress echocardiogram (ultrasound) or nuclear stress test. In patients who are unable to exercise due to some or other reason, a medication that mimics the effect of exercise on heart is used to make it pump harder.
• Cardiac catheterization and angiogram.Narrowing or blockade in coronary arteries can be revealed by this test. The test involves injecting a liquid dye into the arteries of your heart through a long, thin tube (catheter) that’s fed through an artery, usually in your leg, to the arteries in your heart. The arteries become visible on X-ray, as the dye fills your arteries. Any area of blockage can then be revealed.
• Other imaging tests.Other tests that may be employed by doctor to study your arteries include ultrasound, a computerized tomography (CT) scan or magnetic resonance angiography (MRA). These tests are generally reliable to detect hardening and narrowing of large arteries, as well as aneurysms and calcium deposits in the artery walls.

Location of atherosclerosis determines the complications of atherosclerosis. For example:

• Coronary artery disease. When the arteries close to your heart are narrowed by atherosclerosis, you may develop coronary artery disease, which can cause chest pain (angina), a heart attack or heart failure.
• Carotid artery disease.When the arteries close to your brain are narrowed by atherosclerosis, you may develop carotid artery disease, which can cause a transient ischemic attack (TIA) or stroke.
• Peripheral artery disease.When the arteries in your legs or arms are narrowed by atherosclerosis, you may develop circulation problems in your arms and legs called peripheral artery disease. The symptoms of peripheral artery disease include reduced sensitivity to heat and cold and increased risk of burns or frostbite. Very rarely, compromised circulation in your arms or legs can cause tissue death (gangrene).
• Aneurysms.Aneurysms are a serious complication of atherosclerosis that can occur anywhere in your body. An aneurysm is a bulge in the wall of your artery. Aneurysms don’t produce symptoms in most people. Pain and throbbing in the area of an aneurysm may occur and is a medical emergency. Bursting of an aneurysm is troublesome leading to life-threatening internal bleeding. This catastrophic event is usually sudden but a slow leak is possible. Blockage of an artery at some distant point can also occur if a blood clot within an aneurysm dislodges.

The best treatment for atherosclerosis is lifestyle changes that include eating a healthy diet and exercising. But sometimes, medication or surgical procedures may be recommended as well.

Many drugs are available these days that can slow — or sometimes even reverse — the effects of atherosclerosis. Some commonly used drugs are:

• Cholesterol medications.A range of cholesterol medications, including drugs known as statins and fibrates, are available that can aggressively lower low-density lipoprotein (LDL) cholesterol, the “bad” cholesterol. LDL cholesterol can slow, stop or even reverse the buildup of fatty deposits in your arteries. Boosting your high-density lipoprotein (HDL) cholesterol, the “good” cholesterol, may help, too.
• Anti-platelet medications.These drugs reduce the likelihood that platelets will clump in narrowed arteries, form a blood clot and cause further blockage. Main drug used for this purpose is aspirin.
• Beta blocker medications. These medications are commonly used for coronary artery disease patients to decrease their heart rate and blood pressure. They reduce the demand on your heart and often relieve symptoms of chest pain. These drugs are helpful in reducing the risk of heart attacks and heart rhythm problems.
• Angiotensin-converting enzyme (ACE) inhibitors.These drugs lower blood pressure and may help slow the progression of atherosclerosis.
• Calcium channel blockers. These medications lower blood pressure and are sometimes used to treat angina.
• Water pills (diuretics).These drugs lower blood pressure by reducing the blood volume and help in decreasing the progression of atherosclerosis.
• Other medications.If you have any other risk factor like diabetes, your doctor will prescribe medications for that.

More aggressive treatment is required sometimes.Surgical procedures are employed if you have severe symptoms or a blockage that threatens muscle or skin tissue survival. These include:

• Angioplasty and stent placement.A long, thin tube (catheter) is inserted into the blocked or narrowed part of your artery. Another tube or catheter with a deflated balloon on its tip is then passed through the catheter to the narrowed area. The balloon is then inflated, compressing the deposits against your artery walls. To help the artery remain open, a mesh tube (stent) is usually left in the artery.
• Endarterectomy.Fatty deposits must be surgically removed from the walls of a narrowed artery in some cases. This procedure is generally done on arteries in the neck (the carotid arteries), and called a carotid endarterectomy.
• Thrombolytic therapy.A clot-dissolving drug may be used to break the clot if you have an artery that’s blocked by a blood clot.
• Bypass surgery.It is a major surgery on heart arteries and involves creating a graft bypass using a vessel from another part of your body or a tube made of synthetic fabric. With this procedure, blood flow is maintained around the blocked or narrowed artery.

Lifestyle Measures for treatment and Prevention

Lifestyle changes can help you prevent or slow the progression of atherosclerosis.

• Stop smoking.
• Exercise most days of the week.
• Eat healthy foods.
• Lose extra pounds and maintain a healthy weight.
• Manage stress.
• If you have high cholesterol, high blood pressure, diabetes or another chronic disease, work with your doctor to manage the condition and promote overall health.

External Links/References

• http://www.mayoclinic.com/health/search/search
• http://www.patient.co.uk/health/Atheroma.htm
• http://familydoctor.org/familydoctor/en/diseases-conditions/atherosclerosis.html