What is angina?

Angina occurs when the blood flow to your heart decreases and is a symptom of coronary artery disease.  It is also known as angina pectoris or ischaemic chest pain.  It can be described as a pain, heaviness, tightness, pressure or squeezing of your chest.

In the United States, around 9.8 million citizens experience angina annually.  Black women under the age of 65 years are at the most risk of getting an episode of angina.

Angina can usually be controlled by medications and lifestyle modifications.  However, in severe cases, surgical placement of a stent- a tiny tube that props open arteries- may be necessary to improve the blood supply to your heart.

What are the causes of angina?

Your heart muscles need oxygen which is supplied by the coronary arteries to function properly.  Coronary artery disease (CAD) is a condition where your coronary arteries becomes narrowed by fat deposits which are called plaques, resulting in a reduced blood supply to the heart.  There are 3 main types of angina and these include:

• Stable angina: Stable angina is the most common form of angina and is usually triggered by exercises which may be in the form of climbing stairs, walking and physical exercises.  These increases your heart’s demand of oxygen.  However, as the coronary arteries are narrowed, your heart’s demand for oxygen is not met, resulting in angina.  In addition, stable angina can be caused by emotional stresses, heavy meals, cold temperatures and cigarette smoking.  It usually lasts for a few minutes and is relieved by rest.  It is not a heart attack but may be a sign that you are about to get one.

• Unstable angina: This type of angina occurs even when you are at rest.  The pain lasts for a longer time and is stronger.  In addition, it is likely to come back again and again.  This may indicate that a heart attack is imminent and requires emergency treatment.
• Variant angina: This type of angina is also known as Prinzmetal’s angina.  It is a rare type of angina which occurs at night while you are resting or sleeping.  This arises due to sudden spasm of your coronary arteries, resulting in temporary narrowing of the arteries, causing severe chest pain.

What are the risk factors for angina?

There are several factors which may increase your risk of developing angina and these include:

• Advanced age
• High blood pressure
• Obesity
• Stress
• High cholesterol level
• A family history of heart disease
• Diabetes
• Cigarette smoking
• Sedentary lifestyle

What are the other signs and symptoms associated with angina?

The other signs and symptoms associated with angina include:

• Nausea.
• Sweating during the angina episode.
• Shortness of breath.
• Light-headedness.
• Fatigue.
• Vomiting.
• Heartburn
• Chest pain that spreads to your shoulders, neck. Arms and back.

There are other conditions or diseases which may resemble angina and these include:

• Acute gastritis
• Anxiety disorders
• Anaemia
• Aortic dissection
• Biliary colic
• Cholecystitis
• Cocaine toxicity
• Coronary artery atherosclerosis
• High blood pressure (hypertension)
• Kawasaki disease
• Mitral valve regurgitation
• Peptic ulcer disease
• Panic disorder
• Pulmonary arterial hypertension

Making a diagnosis

To make a diagnosis, your doctor will first take a detailed history from you to know more about your symptoms.  After the history taking, your doctor will perform a thorough physical examination to look for signs of angina.  To confirm the diagnosis, your doctor will order some tests and these include:

• Electrocardiography (ECG or EKG): An ECG measures the electrical activity of your heart.  Using the ECG, your doctor may determine if there is any rhythm abnormalities within your heart, any interruption or reduced blood supply to your heart or if you are having a heart attack.
• Blood tests: A sample of your blood be taken to test for certain enzymes which are released when your heart muscles are not getting enough oxygen due to a poor blood supply.  This is especially useful during or after a heart attack.
• Chest radiography: This test is done to assess whether your heart is enlarged or if there is water within your lungs which may be the complications of heart conditions.

• Exercise stress test: This test involves your doctor measuring your blood pressure and obtaining an ECG while you are walking on a treadmill or pedalling on a stationary bicycle.  This is to assess your heart function while exercising to determine if there is any problem with the blood supply to your heart.
• Echocardiography: This test uses sound waves to obtain images of your heart.  This test enables you doctor to assess the blood flow within your heart and it can also be done during the stress test.
• Nuclear stress test: This test is similar to a regular stress test.  However, a radioactive substance is injected into your bloodstream.  This is to determine which part of your heart is not getting enough blood supply as the part having poor blood supply will not have much radioactive substances there.
• Coronary angiography: This test involves your doctor injecting a dye that is visible by x-ray machines, into your heart’s blood vessels.  This is to assess the blood flow within your coronary arteries by taking several pictures (angiograms) of the arteries.  It is often part of a procedure called cardiac catheterisation, during which your doctor measures the blood pressure and blood flow within your coronary arteries.  In addition, during the same procedure, angioplasty can be done, which involves your doctor placing a stent to open up the narrowed part of the arteries.

• Cardiac Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) scans: These tests may also be used to assess the blood flow and size of your heart.

What are the treatments of angina?

The treatments of angina usually involves lifestyle modifications, medications, medical and surgical procedures.  The lifestyle modifications can be done to improve or slow down the progression of the condition include:

• Smoking cessation.
• Losing weight.
• Eating plenty of fruits and vegetables.
• Starting a safe exercise plan after having talked to your doctor.
• Limit alcohol consumption.

The medications that can be used to treat angina include:

• Aspirin: Aspirin decreases your blood’s ability to clot, therefore making it easier for your blood to flow through the arteries.
• Nitrates: Nitrates work by widening your blood vessels, therefore increasing the blood supply to your heart.  An example include nitroglycerin tablets which you put under your tongue.
• Antiplatelets: This class of drug is also known as blood thinners or clot-preventing drugs.  They prevent clot formation by preventing platelets to stick together.  Examples include clopidogrel and ticagrelor.
• Beta blockers: This class of drug works by blocking the effect of the hormone adrenaline which is also known as epinephrine.  Therefore, it makes you heart beat slower and with less force which will decrease your blood pressure.

• Calcium channel blockers: This class of drug widens and relaxes your blood vessels which will increase the blood flow to your heart.
• Statins: These drugs are used to lower your blood cholesterol level.  This is important to prevent or reabsorb the cholesterol that has accumulated in the plaques within your coronary arteries, therefore preventing further narrowing of the blood vessel.
• Medication to lower the blood pressure: Angiotensin 2 Receptor Blockers (ARBs) and Angiotensin-Converting Enzyme (ACE) inhibitors are used to lower your blood pressure in case you suffer from hypertension, chronic kidney disease, heart failure or diabetes.

The medical procedures and surgeries that can be done to treat angina include:

• Angioplasty: This procedure is also known as percutaneous coronary intervention (PCI).  During this procedure, a tiny balloon is inserted into the narrowed artery and is inflated to widen that segment of the artery, after which a stent (small wire mesh coil) is inserted to keep that portion of the artery open.  If lifestyle modifications and medications are not enough to treat the angina, this medical procedure can be useful in relieving your symptoms.
• Coronary artery bypass graft (CABG) surgery: This surgical procedure involves your doctor taking a vein from your legs to bypass the narrowed or blocked coronary arteries.  This is usually the last treatment option considered when all other methods were not successful or in cases where the coronary arteries are blocked in too many places to consider stenting.

Expectations (prognosis)

Angina can be treated if you seek medical advice early and follow your treatment plan without fail.  Unfortunately, every 25 seconds, someone suffer from angina and every 1 minute, some dies from one.  In 2005, out of every 5 deaths, 1 was due to coronary heart disease.  Therefore, it is very important to adopt a healthy lifestyle and do regular check-ups at your doctor’s office to prevent the condition or to detect the condition early.

J. Alastair, I. and Simon, M., 2016. Davidson's Essentials of Medicine. 2nd ed. London: ELSEVIER.

Parveen, K. and Michael, C., 2017. Kumar & Clarks Clinical Medicine. 9th ed. The Netherlands: ELSEVIER.

Alaeddini, J., 2018. Angina Pectoris: Practice Essentials, Background, Pathophysiology.