Angina pectoris is considered a symptom of coronary artery disease. It is a medical term which refers to sudden chest discomfort, pressure or pain. This occurs due to low blood supply to the muscles of the heart because of the blockage in the arteries of the heart. Due to insufficient blood supply, cardiac cells lack oxygen and start to degenerate. As the number of cells degenerates, it leads to the death of individuals. Angina pectoris is further divided into 4 types based on the level of the disorder or the chest pain. The types are Stable Angina, Unstable Angina, Microvascular Angina and Variant Angina.

Classification of angina pectoris

Depending upon the pathophysiology of angina pectoris, it can be classified into four types;

Stable angina

It is also called effort angina. Discomfort can occur during the activity. Symptoms generally disappear after rest or there are minimal symptoms at rest. Stable angina occurs due to obstruction of coronaries by atheroma. This obstruction can be caused by plaque (a mixture of fat, cholesterol, calcium and other substances) which narrows the arteries and as a result, the heart would not get enough blood.

Symptoms of stable angina

• Anxiety
• Sweating
• Shortness of breath
• Fatigue
• Nausea
• Dizziness

Factors responsible for stable angina

• Sedentary lifestyle
• Obesity( increased weight)
• Diabetes (high Blood glucose levels)
• High blood pressure 
• High cholesterol 
• Any previous encounter with heart disease

Unstable angina

 It is also called crescendo angina. It is an acute coronary syndrome where angina got worse even at rest. It occurs due to spasms and partial obstruction of coronaries.

Symptoms of unstable angina

• Tight pain in the chest which slowly spread towards the upper arm and shoulder
• Sweating 
• Anxiety 
• Shortness of breath
• Chest pain doesn’t stop after rest

Factors responsible for stable angina

• High blood pressure
• Low-density lipoprotein cholesterol (LDL)
• High-density lipoprotein cholesterol (HDL)
• Diabetes (high blood glucose level)
• Obesity 
• Using any form of tobacco

Microvascular angina

It is also called syndrome X. It occurs due to spasms within the walls of blood vessels. The heart’s smallest arteries got affected in this condition.

Symptoms 

• Discomfort in the chest like heaviness, tightness or pressure.
• Difficulty breathing
• Stomach pain
• Nausea 
• Dizziness

Factors responsible for microvascular angina

• Lack of physical activity 
• High blood pressure 
• Unhealthy blood cholesterol level
• Unhealthy diet and lifestyle
• Age factor

Variant angina

It is also known as angina inversa. It mostly affects younger age groups. It probably occurs due to a spasm of the coronary artery. It mostly occurs at odd times during the day or night.

Symptoms of variant angina

• Intermittent chest pain 
• Rapid, irregular or skipped heartbeat.
• Trouble breathing 
• Nausea 
• Sweating 

Factors responsible for variant angina

• Medications that restrict are narrow the blood vessels such as migraine
• Stress
• Use of narcotics drugs
• Excessive exercise 
• Exposure to cold

Diagnosis of angina pectoris 

• Electrocardiogram (ECG): The electrocardiogram as the name indicates is a process to record electrical impulses of the heart.  These electric impulses are used to identify heart abnormalities like ischemia.
• Angiography: It is a process in which a thin, long tube made of plastic is inserted into an artery of the wrist using a needle. The catheter is sent into the coronary arteries by a wire along with a contrast material injected directly into the arteries to observe if the blood channels are narrowed. X-rays are used to acquire images of these blood vessels with contrast material.
• Blood tests:  There are Some specific enzymes, such as troponin that might enter the bloodstream after a heart attack or acute angina. These enzymes can be detected by tests. Blood tests can reveal fluctuations in levels of cholesterol, LDL, and triglycerides. These fluctuations can be a risk factor for coronary artery disease and, as a result, angina.

Treatment of angina pectoris 

• Healthy lifestyle – Angina pectoris can be managed by adopting certain lifestyle changes like maintaining a healthy weight, consuming a balanced low-fat diet, quitting smoking, and learning stress management techniques.
• Angioplasty and vascular stunts – It’s a procedure that involves using balloons with stents which are optional, and can be used to open up clogged coronary arteries. This procedure will improve blood flow to the heart by opening the clogged arteries. Coronary artery bypass grafting surgery is also a technique that improves blood flow to the heart by redirecting blood flow around a blockage or obstruction in the coronary arteries of the heart by using a vein or artery from some other part of the body.

Conclusion 

Angina pectoris is a form of chest pain caused due to low blood supply to the heart muscle. Because of the reduction in blood flow, the heart muscle does not receive enough oxygen, resulting in chest pain. One of the most prevalent causes of angina is coronary artery disease, which causes constriction of the coronary arteries that are the main source of providing blood and oxygen to the heart muscle. Lifestyle changes can be used to manage Angina Pectoris like following a balanced diet and weight. Angioplasty is also a technique that can be used to maintain angina pectoris.