Heart Attack

A heart attack, also known as acute myocardial infarction, results from a blockage of the arteries that supply blood to the heart. This sudden cut-off of the blood supply devoids the heart muscle of oxygen and nutrients necessary to function leading to chest pain, also known as angina. 

Heart diseases are a growing epidemic in the world today. Cardiovascular diseases are the topmost cause of deaths globally. They have led to over 17.9 million deaths in 2016 alone, with three-fourths of the deaths occurring in the middle income and developing countries. Lifestyle changes and urbanization have led to the rise in heart problems. India records 0.5 million deaths each year, and 20% of these deaths are due to heart diseases.

(Read More - Heart valve replacement)

The type and intensity of symptoms vary among individuals. Some people may not have any complaints, while others may complain of severe chest pain. Many people experience warning symptoms a few days or weeks before a heart attack, which includes recurrent chest pain, fatigue, and shortness of breath.

Often, the first symptom is a pain in the left side of the chest radiating to the left arm, jaw, shoulders, or all these areas. Pain is long lasting and may be accompanied by:

• Shortness of breath.
• Nausea.
• Vomiting: several people assume that the vomiting is due to indigestion and may be relieved by belching or after taking antacids.
• Discomfort.
• Pale skin.
• Weak pulse.
• Fluctuating blood pressure.
• Restlessness.
• A feeling of doom and anxiety.

(Read More - Myocarditis treatment)

A heart attack occurs when the blood supply to a part or whole of the heart is blocked suddenly. The main reason for an obstruction is coronary heart disease (CHD).

Coronary Heart Disease

In CHD, there is deposition of cholesterol-rich plaque in the walls of the arteries. The plaque may either rupture or harden over a period of time. As the plaque hardens and builds up further, it causes narrowing of the arteries, which blocks the oxygen supply. This is one of the chief causes of a heart attack. The causes of CHD are:

• High cholesterol.
• Obesity.
• Smoking.
• Diabetes.
• Sedentary lifestyle.
• Faulty eating habits – high fat and high carbohydrate diet.

Risk Factors

There are three most important risk factors that may lead to the development of heart diseases: smoking, high blood pressure, and high cholesterol. Risk factors can be classified into non-modifiable (which cannot be changed) and modifiable (which can be changed) factors, which can contribute towards the formation of fat deposits in the heart vessels.

Non-modifiable Risk Factors

• Age
  Men above 45 years and women above 55 years of age have a higher risk of developing heart disease.
• Family History
  The risk of developing heart disease increases if there is a strong family history of the disease and is even greater if the father or brother was diagnosed before the age of 55 years or if the mother or sister has heart illnesses before 65 years of age.
• Preeclampsia
  It is a condition that may occur during pregnancy. High blood pressure and high amounts of protein excretion in the urine are the two main features of preeclampsia. A woman diagnosed with preeclampsia has a lifelong risk of developing high blood pressure, heart diseases, and heart attack as well as heart failure.

(Read More - Where does the heart get its energy)

Modifiable Risk Factors

• Smoking
  Smoking, in general, is harmful to every organ of the body. It affects the heart, lungs, mouth, eyes, bones, bladder, reproductive and digestive organs. Exposure to any amount of smoke can cause damage to the structure and function of the heart muscle and blood vessels. Exposure to passive smoke (inhaling smoke when someone else is smoking) causes equal damage as active smokers (people who smoke). This can raise the chances of developing atherosclerosis, which is the formation of plaques that narrow the arteries. With time, the oxygen supply to the parts of the organs gets restricted. Smoking may also lead to plaque formation in the arteries that supply blood to the head, brain, limbs, and other organs. Such people are at a higher risk of getting heart attacks, heart diseases, and stroke. Smoking along with other risk factors, such as obesity, high blood pressure, and high levels of cholesterol in the blood can further raise the risk of developing a heart disease.
• High blood pressure
  High blood pressure, also known as hypertension, is a condition in which the flowing blood exerts pressure on the vessel walls that is higher than normal. Excessive salt in the diet; stress; medications, such as birth control pills and medicines for a common cold; a sedentary lifestyle; and unhealthy eating habits increase the risk of developing hypertension and thereby CHD. Failure to control high blood pressure can lead to complications including heart diseases, heart attacks, stroke, and kidney failure.
• High blood cholesterol
  In this condition, the level of lipids or bad fats is very high in the blood. This occurs due to a poor lifestyle along with genetic traits. Certain medical conditions, such as diabetes, obesity, hypothyroidism (a decreased production of the thyroid hormone), polycystic ovary disease (development of fluid-filled sacs in the ovaries), kidney diseases, and HIV, can also lead to high levels of cholesterol in the blood.
• Obesity
  Obesity is linked to an increased risk of developing high cholesterol levels, high blood pressure, and diabetes. All these factors influence the risk of developing heart diseases in the future.
• Sedentary lifestyle
  Lack of adequate physical activity and leading a sedentary daily routine poses a person at a higher risk of developing high blood pressure and cholesterol and causes weight gain. Daily exercise helps maintain a steady weight and reduce the risk for several lifestyle-related illnesses. It also helps strengthen the heart muscle and increases oxygen supply to the lungs and body. Due to increases physical activities, the metabolism of cholesterol and the excretion of bad cholesterol are increased, thus reducing plaque formation.
• Improper diet
  A diet rich in fats, salts, and cholesterol increases the risk of lifestyle-related diseases, which could lead to the development of a heart disease.
• Diabetes and insulin resistance
  In diabetes, the blood has high glucose levels. Sustained elevated levels of blood glucose can lead to complications, such as heart disease, damage to the nerves, eyes, and kidneys. The insulin hormone secreted by the pancreas after every meal helps to break down blood glucose present in the muscle, liver, and fat cells. This helps in keeping the blood glucose level within the normal range. During insulin resistance, the muscle cells, fat cells, and liver are not able to respond to insulin. As a result, the pancreas release more insulin to digest glucose.

(Read More - What to eat for a stronger heart)

The World Health Organization suggests the following strategies to prevent heart attacks:

• Following a regular diet and exercising at least five days a week for 30 minutes a day.
• Maintaining a healthy diet full of fresh, raw fruits and vegetables.
• Quit smoking and limit alcohol consumption.
• Ensuring regular health check-ups every year if you are healthy and every six months if you already have a disease.
• Take medications for your medical condition on time to avoid its worsening and to prevent complications.

(Read More - Cardiac Arrest treatment)

A heart attack can be diagnosed with the help of the following investigatory tests:

Electrocardiography

An ECG is the first investigation conducted within 10 minutes of the onset of symptoms. The doctor should be able to read an ECG carefully as the changes may be very subtle and can often be missed. If the symptoms are very characteristic of a heart attack, the ECG will have a specificity of up to 90%.

(Read More - Ventricular Tachycardia treatment)

Cardiac Markers

During a heart attack, there are certain enzymes of the heart (troponin, myoglobin), which are elevated and released into the bloodstream. These enzymes are released at different intervals after a heart attack and hence these tests are very specific and sensitive in nature for detecting a heart attack rapidly.

(Read More - Bradycardia treatment)

Coronary Angiography

Coronary angiography is performed immediately in patients with a severe heart attack. Patients with a mild heart attack also undergo an angiography within 48 hours of hospitalisation. The angiography involves the injection of a dye within the heart’s blood vessels that will reveal the sites of blockage.

(Read More - Tachycardia treatment)

Other Investigations

Other investigations, such as chest X-ray, can reveal the size of the heart or determine the presence of fluid in the lung cavity; two-dimensional echocardiography, cardiac magnetic resonance imaging, or computerised tomography scan may also be advised to evaluate the extent of the blockage of the blood vessels.

(Read More - Aortic Stenosis treatment)

A heart attack can be treated only in a hospital setup. The following treatment modalities are used in the case of a heart attack:

Medications

Medications include anti-platelet drugs drugs that prevent the accumulation of platelets on the blood vessel walls), blood thinners, anticoagulants (clot-busting medications), oxygen therapy, and painkillers for relieving the symptoms of heart attack. Medications to reduce blood pressure and control cholesterol are also administered, which help in reducing cardiac load and meet the oxygen demand.

(Read More - Homeopathic treatment for heart attack)

Surgery

Along with medications, one of the below-mentioned procedures may also be performed:

• Coronary angioplasty
  Along with coronary angiography, angioplasty may also be performed during which a stent is inserted in the blocked vessel. The stent will open the blocked artery, which restores blood flow.
• Coronary artery bypass surgery
  During a bypass surgery, doctors will surgically create new blood supply around the blocked artery by sewing arteries or veins in place from other healthy parts of the body, which ensures that blood will bypass the blocked section.

(Read More - Homeopathic treatment for Chest Pain)

Lifestyle management

Lifestyle modification is the best way to improve heart health. The following steps can aid in reducing the risk of developing heart disease in future:

• Perform daily exercise activities, such as running, jogging, swimming, and yoga, to provide good amounts of oxygen to the body and lower blood pressure. Check with the doctor before starting any activity.
• Maintain a healthy weight.
• Quit smoking. Avoid passive smoke.
• Limit alcohol to not more than 14 units in a week.
• Maintain a diet low in sodium and fats. Including more fruits, vegetables, and fibre keeps the heart healthy.
• Go for regular health check-ups and periodic blood pressure monitoring.
• Manage stress at the workplace and at home.

(Read More - Ayurvedic treatment for Chest Pain)

Prognosis

Heart attacks are a medical emergency with almost 25% to 30% of the persons dying before they reach the hospital. The duration of recovery from a heart attack can be long. During the recovery period, it is important to get support from a range of professionals, such as nurses, dieticians, physiotherapists, and counsellors to ensure proper care.

Complications

Complications of a heart attack include:

• Arrhythmias
  Arrhythmia refers to an irregular heartbeat due to injury to the heart muscles.
• Heart blocks
  Electrical signals cannot travel from one area of the heart to the other, leading to defective pumping.
• Heart failure 
  Caused after a heart attack, wherein the heart muscle cannot pump blood.
• Cardiogenic shock 
  The heart muscle is severely damaged, and it cannot pump enough blood for regular functioning.
• Heart rupture
  Heart muscles, valves, or walls split or rupture. In this case, the outcome is poor, with almost 50 % of deaths occurring within five days of the rupture.

(Read More - Aortic valve repair)