Atherosclerosis

 Atherosclerosis

Formation of plaque inside the arteries (blood vessels carrying oxygen-rich blood to the heart and other body parts) is referred to as a state of atherosclerosis. With time, the plaque Stiffen and Shrinkage the arteries. As the arteries are narrowed, the flow of oxygen-rich blood to heart as well as to other areas of the body is reduced or stopped.

Atherosclerosis may lead to further complications like heart attack, stroke, or even death. 

Causes 

Atherosclerosis is a slow, progressive condition and is always present in the body up to some level. The exact mechanism of atherosclerosis is not known but it is believed ved that it starts with damage or injury to the inner layer of an artery. These damages can be caused by: 

1) High blood pres 

2) High cholesterol level 

3) High triglycerides, a type of fat (lipid) in the blood, 

4) Smoking and other sources of tobacco, 

5) Insulin resistance, obesity, or diabetes, and 

6) Inflammation from diseases, such as arthritis, lupus, and infections or inflammation of unknown cause.

 Symptoms 

Mild atherosclerosis is usually asymptomatic, Moderate to severe atherosclerosis have symptoms depending on the arteries that are affected. Some of the common symptoms are: 

1) Pain or pressure feeling in the chest (angina), in case atherosclerosis affects the arteries in the heart, 

2) Numbness or weakness in arms or legs, temporary loss of vision in one eye, drooping muscles of face or difficulty in speaking or slurred speech in case atherosclerosis affects the arteries supplying the brain. 

3) High blood pressure sometimes even results in kidney failure, in case atherosclerosis affects the arteries supplying the kidneys.

Diagnosis 

In physical examination, the physician diagnoses the signs of narrowed, enlarged, or hardened arteries: 

1) Below the narrowed area of the artery, either the pulse is absent or a weak pulse is generated. 

2) The blood pressure in the affected limb is low, and

 3) On hearing through stethoscope, whooshing sounds (bruits) are heard over the affected arteries. After a physical examination, the physician may suggest one or more of the following diagnostic tests: 

1) Blood Tests: The increased cholesterol and blood sugar level which may increase the risk of atherosclerosis is detected by blood tests. 

2) Doppler Ultrasound: A special ultrasound device Doppler ultrasound is used to measure the blood pressure at various points of arm or leg. This measurement helps in detecting the degree of any blockage and the speed of arterial blood flow. 

3) Ankle-Brachial Index: This test determines whether or not the arteries in legs and feet are affected. A comparison belween the ankle blood pressure and the arm blood pressure is made, which is termed as the ankle-brachial index. If the difference between the two is not normal, presence of peripheral vascular disease is suspected which may be the result of atherosclerosis. 

4) Electrocardiogram (ECG): The electrical signals travelling through the heart are recorded by ECG. It also indicates the history of a heart attack, If the signs and symptoms of the individual appear during physical activity, he/she is asked to walk on a treadmill or ride a stationary bike while performing the ECG. 

5) Stress Test: This test (also termed as exercise stress test), reveals the heart performance during any physical activity. In this test, the heart rhythm, blood pressure, and breathing rate of the individual are recorded while he/she walks on a treadmill or ride a stationary bike. 

6) Cardiac Catheterisation and Angiogram: This test is used to detect the narrowing and blockage of coronary arteries. In this test, a catheter (a long, thin tube) filled with a liquid dye is fed through an artery (mostly of a leg) to reach the arteries in the heart. When the arteries become stained with the dye, they can be seen on X-ray, which reveals any narrow or biockage in the coronary arteries. 

7) Other Inmaging Tests: Other imaging techniques like ultrasound, Computerised Tomography (CT) scan, or Magnetic Resonance Angiography (MRA) are performed to determine any hardened and narrowed large arteries, any kind of swelling, and deposition of calcium on artery walls. 

Treatment 

The clinical management for atherosclerotic patients involves changing the current lifestyle of the patient like dietary modifications (such that the quantity of cholesterol and fat is decreased) and exercise. They improve the health of blood vessels and the heart. Administration of drugs to prevent the worsening of atherosclerosis may be needed. Such drugs include: 

1) Statins and fibric acid derivatives (cholesterol-lowering drugs). 

2) Antiplatelet drugs and anticoagulants (aspirin, to prevent clotting of blood and hence, clogging of the arteries), 

3) Beta blockers or calcium channel blockers (to reduce blood pressure). 

4) Diuretics (to lower the blood pressure), and 

5) Angiotensin Converting Enzyme (ACE) inhibitors (to prevent narrowing of the arteries). 

Surgery may be required in case of severe symptoms or in case of endangered skin or muscle tissue. The possible surgeries include: 

1) Bypass Surgery: This is performed by using a vessel from a different site in the body or a synthetic tube to divert blood around the blocked or narrowed artery. 

2) Thrombolytic Therapy: This involves injection of a drug into the affected artery to dissolve the blood clot.

3) Angioplasty: This is performed by using a catheter and a balloon for expansion of the artery, and sometimes involves jnsertion of a stent to avoid closure of the arteries. 

4) Endarterectomy: This procedure involves surgical removal of fatty deposits from the artery. 

5) Atherectomy: This procedure involves elimination of plaque from the arteries by using a catheter having a sharp blade at one end.