It is not a disease itself, but rather a likely symptom of coronary artery disease, the most common type of heart disease. The lack of oxygen-rich blood to the heart is usually a result of narrower coronary arteries due to plaque build-up; a condition called atherosclerosis.
Narrow arteries increase the risk of pain, coronary artery disease, heart attack, and death.
Angina may manifest itself in the form of an angina attack, pain, or discomfort in the chest that typically lasts from 1-15 minutes. The condition is classified by the pattern of attacks into stable, unstable, and variant angina.
Contents of this article:
Fast facts on angina
- Angina is not a disease in itself, but a symptom of heart disease.
- Attacks are caused by reduced oxygen in the blood reaching the heart.
- Symptoms include tightness and difficulty breathing.
- Treatment options can range from lifestyle changes to medications.
Types of angina
Stable (or chronic) angina
Stable angina occurs when the heart is working harder than usual, for instance, during exercise. It has a regular pattern and can be predicted to happen over months or even years. Rest or medication relieves symptoms.
Unstable angina does not follow a regular pattern. It can occur when at rest and is considered less common and more serious because rest and medication does not relieve it. This version can signal a future heart attack within a short time - hours or weeks.
Variant and microvascular angina
Variant (Prinzmetal's) angina and microvascular (smallest vessels) angina are rare and can occur at rest without any underlying coronary artery disease. This angina is usually due to abnormal narrowing or relaxation (spasm) of the blood vessels, reducing blood flow to the heart. It is relieved by medicine.
Causes of angina
Atherosclerosis - a buildup of plaque around the artery wall - is the most common cause of angina.
Angina is most frequently the result of underlying coronary artery disease. The coronary arteries supply the heart with oxygen-rich blood. When cholesterol aggregates on the artery wall and hard plaques form, the artery narrows.
- It is increasingly difficult for oxygen-rich blood to reach the heart muscle as the arteries become too narrow.
- Damage to the arteries from other factors (such as smoking and high levels of fat or sugar in the blood) can cause plaques to build up where the arteries are damaged.
- These plaques narrow the arteries or may break off and form blood clots that block the arteries.
The actual angina attacks are the result of this reduced oxygen supply to the heart. Common triggers include:
- Physical exertion is a common trigger because the heart needs more oxygen than it receives in order to work harder.
- Severe emotional stress.
- A heavy meal.
- Exposure to extreme temperatures.
- Smoking may trigger angina attacks.
Unstable angina is often caused by blood clots that partially or totally block an artery. Larger blockages may lead to heart attacks. As blood clots form, dissolve, and form again, angina can occur with each blockage.
Variant angina occurs when an artery experiences a spasm that causes it to tighten and narrow, disrupting blood supply to the heart. This can be triggered by exposure to cold, stress, medicines, smoking, or cocaine use.
Symptoms of angina
Angina is usually felt in the chest region as:
- burning or aching across the chest, usually starting behind the breastbone
This pain often spreads to the neck, jaw, arms, shoulders, throat, back, or even the teeth.
Patients may also complain of symptoms including:
Stable angina usually lasts a short period, and may feel like gas or indigestion. Unstable angina occurs at rest, is surprising, lasts longer, and may worsen over time. Variant angina occurs at rest and is usually severe.
Angina risk factors and prevention
Those at an increased risk of coronary artery disease are also at an increased risk of angina. Risk factors include:
- unhealthy cholesterol levels
- hypertension (high blood pressure)
- tobacco smoking
- being overweight or obese
- metabolic syndrome
- sedentary lifestyle
- being over 45 for men and over 55 for women
- family history of early heart disease
Angina can be prevented by changing lifestyle factors and by treating related conditions that exacerbate or contribute to angina symptoms. To prevent or delay angina, eat healthfully, quit smoking, be physically active, and learn how to handle stress.
Also, make sure to receive proper treatment for high blood cholesterol, high blood pressure, diabetes, and obesity.
Treatments for angina
Angina treatments aim to reduce pain, prevent symptoms, and prevent or lower the risk of heart attack. Medicines, lifestyle changes, and medical procedures may all be employed. Lifestyle changes recommended to treat angina include:
- stopping smoking
- controlling weight
- regularly checking cholesterol levels
- resting and slowing down
- avoiding large meals
- learning how to handle or avoid stress
- eating fruits, vegetables, whole grains, low-fat or no-fat dairy products, and lean meat and fish.
Medicines called nitrates (like nitroglycerin) are most often prescribed for angina. Nitrates prevent or reduce the intensity of angina attacks by relaxing and widening blood vessels.
Other medicines may be used such as:
- beta blockers
- calcium channel blockers
- ACE (angiotensin-covering enzyme) inhibitors
- oral anti-platelet medicines
High blood pressure medications may also be prescribed to treat angina. These medicines are designed to lower blood pressure and cholesterol levels, slow the heart rate, relax blood vessels, reduce strain on the heart, and prevent blood clots from forming.
In some cases, surgical medical procedures are necessary to treat angina. A heart specialist may recommend angioplasty. Coronary artery bypass grafting is another standard procedure; this is surgery where the narrowed arteries in the heart are bypassed using a healthy artery or vein from another part of the body.
Diagnosis of angina
A correct diagnosis for chest pain is important because it can predict the likelihood of having a heart attack. The process will start with a physical exam as well as a discussion of symptoms, risk factors, and family medical history.
A physician who is suspicious of angina will order one or more of the following tests:
- Electrocardiogram (EKG) - records electrical activity of the heart and can detect when the heart is starved of oxygen.
- Stress test - blood pressure readings and an EKG while the patient is increasing physical activity.
- Chest X-ray - to see structures inside the chest.
- Coronary angiography - dye and special X-rays to show the inside of coronary arteries (dye is inserted using cardiac catheterization).
- Blood tests - to check levels of fats, cholesterol, sugar, and proteins.