For an organ that is only slightly bigger than a clenched fist, the heart is responsible for pumping nearly 2,000 gallons of blood a day. Diseases of the heart and its blood vessels, collectively known as cardiovascular diseases (CVD), are one of the leading causes of death worldwide. One in every four deaths in India is due to an underlying heart problem.

The heart is like a reservoir with multiple blood vessels or arteries branching out to every part of your body, carrying oxygenated blood. Every organ in your body, including the heart, requires oxygen to function. The arteries transport oxygenated blood and nutrients to all tissues. If these vessels are blocked, blood flow gets restricted, cutting off the oxygen supply to the tissues and organs. Deposition of plaque within the walls of the arteries is a common reason for blockage; such a condition is called atherosclerosis.

What is atherosclerosis?

A build-up of fats and cholesterol on the inside of the arterial walls can lead to narrowing of the diameter of the vessels and therefore, the blood flow gets restricted. This deposited plaque grows slowly and can eventually build up enough to block a blood vessel. If the plaque ruptures or breaks down, a blood clot forms around it, which further narrows the blood vessel or blocks it entirely.

Atherosclerosis can occur in any blood vessel in the body. Symptoms are usually specific to the organ whose blood supply has been compromised as a result of the blockage. When this occurs in arteries that supply oxygenated blood to the heart, it can lead to coronary heart disease — the primary cause of myocardial infarction or heart attack. The heart cells begin to die due to the lack of oxygen, giving way to a “squeezing” sensation in the chest, which is the hallmark symptom of a heart attack. 

Causes of atherosclerosis

Though the exact cause is unknown, certain factors make you more vulnerable to atherosclerosis over time.

High cholesterol: Prolonged presence of high levels of low-density lipoprotein (LDL) cholesterol and triglycerides can increase the risk of plaque accumulation within the blood vessels.

High blood pressure: It can increase the force exerted on the walls of arteries, damaging them and making them more prone to plaque build-up.

Smoking: Chemicals in cigarettes can damage the cells in the blood. It can also affect the structure and function of the blood vessels.

Diabetes: Prolonged exposure to high blood sugar levels can damage the blood vessels, and increase the risk of developing atherosclerosis.

Family history: You are at a higher risk if you have a family history of heart problems.

Age: With advancing age, the walls of blood vessels lose their elasticity and tend to become stiff. This disturbs the smooth flow of blood in the vessels, leading to the accumulation of plaque and the formation of clots.

Unhealthy diet: Diet high in salt, sugar, saturated and trans fats, or cholesterol can increase the risk of atherosclerosis.

Lack of physical activity: A sedentary lifestyle can hamper blood circulation. It can lead to increased production of reactive oxygen species (ROS), which are chemicals produced by your body. If present in excess, they can contribute to the risk of atherosclerosis.

What symptoms should you watch out for?

Since the plaque buildup is gradual, symptoms may not manifest immediately. Often, signs only become evident when a complete blockage of oxygen supply to tissue has already occurred, and they vary depending on the artery that has been compromised. 

For instance, if the arteries supplying the heart muscle are affected, symptoms may include angina (short-term pain in the chest) or a heart attack. The commonest symptoms are:

1. Chest pain
2. Shortness of breath
3. Pain in shoulders, jaw, arms, back, and abdomen
4. Irregular heartbeat or arrhythmia
5. Nausea
6. Muscle weakness

A blockage in arteries supplying oxygen to the brain manifests as ischemic stroke. Symptoms  include:

1. Loss of balance
2. Complete or partial loss of sight 
3. Drooping of the face on one side
4. Inability to move limbs of one side
5. Slurring of speech
6. Confusion
7. Unconsciousness
8. Other symptoms related specifically to area of the brain affected

Prevention and treatment

Lifestyle changes: Lifestyle changes are imperative in preventing atherosclerosis and complications related to plaque formation. These include:

1. Weight loss

2. Regular aerobic exercises like walking, jogging, swimming, and yoga, which improve blood circulation, reduce levels of triglycerides and LDL, and also improve heart health. You should aim for at least 30 minutes of physical activity on most days of the week. Around 150 minutes of moderate physical activity or 75 minutes of vigorous physical activity, every week is highly recommended for optimal results.

3. A balanced diet low in saturated fats and refined sugar, and high in fiber helps maintain weight as well as keep a check on LDL levels.

4. You could try one of these diets to help you towards a balanced lifestyle:

DASH diet: The DASH diet is rich in fruits, vegetables, whole grains, and low-fat dairy foods. It includes meat, fish, poultry, nuts, and beans, and limits sugary foods and beverages, red meat, and added fats. In addition to controlling blood pressure, it is designed to be a well-balanced approach to eating for people in general as well as those suffering from obesity and diabetes. 

Mediterranean diet: This diet includes high proportions of olive oil, legumes, unrefined cereals, fruits, and vegetables, moderate to high consumption of fish, moderate consumption of dairy products,  and low consumption of non-fish meat products. 

Any diet, which you are comfortable with and which helps in reducing weight and maintaining blood pressure and blood glucose and lipid levels at optimal levels, works.

5. Quit smoking and reduce consumption of alcohol.

6. Stress management through yoga, meditation, and exercise.

Medication: Depending on the severity of your condition, you may be prescribed some medications to deal with your symptoms better.

1. Statins: For lowering cholesterol levels in the blood.
2. Beta blockers: For reducing high blood pressure.
3. Aspirin or other anticoagulants: To prevent formation of clots.

Surgery: In some extreme cases, an angioplasty or bypass surgery may be required to regain the blood flow.

References
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3. Atherosclerosis (arteriosclerosis). NHS. https://www.nhs.uk/conditions/atherosclerosis/ (accessed Mar 17, 2021).
4. Atherosclerosis. WebMD. https://www.webmd.com/heart-disease/what-is-atherosclerosis#1-2 (accessed Mar 17, 2021).
5. Atherosclerosis. Harvard Health Publishing. 2019. https://www.health.harvard.edu/a_to_z/atherosclerosis-a-to-z (accessed Mar 17, 2021).
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