- What is angina? What does it feel like?
- What are the signs and symptoms of angina? Does it cause pain?
- What causes angina?
- What are the types of angina?
- How is angina diagnosed?
- What is the treatment for angina?
- Angioplasty and coronary artery bypass surgery
- What are other methods are used to evaluate angina?
- Can you die from angina?
- Can angina be prevented?
What is angina? What does it feel like?
- Angina (angina pectoris) describes the pain, discomfort, ache, or other associated symptoms that occur when blood flow to heart muscle cells is not enough to meet its energy needs.
- The classic description of angina is a crushing pain, heaviness or pressure that radiates across the chest, sometimes down the arm, into the neck, jaw or teeth, or into the back. It may be associated with shortness of breath, nausea, vomiting, sweating, and weakness.
- Many people do not use pain as a description for angina, instead describing the sensation as a fullness, tightness, burning, squeezing, or ache. The discomfort may be felt in the upper abdomen, between the shoulders, or in the back. The pain may be felt just in an arm, right, left or both, and may or may not be associated with other symptoms.
- Angina is often brought on by exercise and other strenuous activities and gets better with rest. When the body requires the heart to pump more blood, the heart muscle is asked to do more work and that can cause it to outstrip its energy supply. When the body rests, angina should start to subside.
- Angina tends to progress slowly over time and patients may not recognize that their symptoms are due to heart disease. It may be fatigue and exercise intolerance, the gradually inability to perform work or other activities that had once been easier to do. It may be shortness of breath with activity like walking up steps or uphill. It is worrisome when the pain comes on at rest or at sleep, since it means that little activity is causing enough stress to cause angina symptoms.
- This is the same situation that occurs when muscles in the leg or arm fatigue because of overuse and they begin to ache. The difference is that one can stop lifting or running but the heart cannot stop beating to rest. The other difference is that the symptoms of angina are felt in different ways by different patients and may not be recognized as coming from the heart.
- Unfortunately for some patients, they may have no symptoms at all, even with significant narrowing of their coronary arteries, and they may first present for care in the midst of a myocardial infarction or heart attack, when a coronary artery is completely blocked. This is especially true for women who may have atypical angina symptoms including fatigue, malaise, weakness, and dizziness.
- Angina is a warning sign that the heart muscle is not getting adequate blood supply and oxygen. If unheeded it may lead to a heart attack or myocardial infarction (myo=muscle + cardium=heart + infarct=death).
- The term mesenteric angina may also be used to describe abdominal pain due to decreased blood supply to the intestine from narrowing of the mesenteric arteries that supply the small and large bowel.
- Unfortunately, there are a couple of eponyms that contain the term angina, that have nothing to do with pain from decreased blood flow. Ludwig's angina is a serious infection of the floor of the mouth. Vincent's angina is another term for trench mouth, where painful ulcerations affect the gums, mouth, and tongue.
What are the signs and symptoms of angina? Does it cause pain?
Classic angina is described as chest pressure that radiates down the arm, into the neck or jaw and is associated with shortness of breath and sweating. However, patients may use different words to describe the pain, including pain, heaviness, tightness, ache, and fullness. The location may or may not be in the chest; instead it may be described in the upper abdomen, back, arms, shoulder, or neck.
Typical angina symptoms should be made worse with activity and should resolve or get better with rest.
Angina may not have any pain and instead may present as shortness of breath with exercise, malaise, fatigue, or weakness. Patients with diabetes have an altered sensation of pain and may have markedly atypical symptoms. Women may not have the same angina constellation of symptoms as men.
What causes angina?
The heart gets its blood supply from coronary arteries that branch off the aorta just as it leaves the heart. The coronary arteries run along the surface of the heart, branching into smaller and smaller blood vessels as they supple each muscle cell of the heart. The most common reason a patient complains of angina is because of narrowed coronary arteries caused by atherosclerotic heart disease (ASHD).
Cholesterol plaque gradually builds on the inner lining of a coronary artery, narrowing its diameter and decreasing the amount of blood that can flow past the blockage. If the heart is asked to do more work and pump harder and faster, enough oxygen may not be able to be delivered beyond the blockage to meet the energy demand of the myocardium and this can cause the symptoms of angina to occur.
If a plaque ruptures, a blood clot may form that completely occludes the coronary artery and prevents any blood flow to the section of the heart muscle that the artery supplies. This is called a heart attack or myocardial infarction and is a medical emergency. Heart muscle that loses its blood supply will die and be replaced with scar tissue that is unable to contract. This may decrease the heart's ability to pump as strongly as before. As well, heart muscle that loses its blood supply can become irritable and result in heart rhythm disturbances like ventricular fibrillation or ventricular flutter that can result in sudden cardiac death.
Because each beat of the heart not only sends blood to the body, but also to itself, there are a variety of systems in the body and within the heart that have to function normally to deliver oxygen to the heart muscle. Should any of them, either individually or in combination, fail to perform adequately, angina may occur. Examples include the following:
- The electrical system of the heart needs to be able to generate a heartbeat that is neither too slow (bradycardia) nor too fast (tachycardia). There may be an intrinsic problem with the heart's electrical conducting system. Atrial fibrillation with rapid ventricular response, atrial flutter, and ventricular tachycardia are too fast rates that can be associated with chest pain, shortness of breath, and other angina symptoms. Complete heart block can make the heart beat too slowly. The abnormal heart rhythm may be due to electrolyte or hormone abnormalities, medications, or toxic ingestions (for example cocaine overdose).
- Heart valves need to allow blood to flow between heart chambers and to the body and lungs in the right direction and at the right speed. This is especially true of the aortic valve that controls blood leaving the heart into the aorta. Severe aortic stenosis or narrowing of the aortic valve, may not allow enough blood to leave the heart with each heartbeat to provide blood flow into the coronary arteries.
- The heart muscle has to be able to have an adequate squeeze or strength to pump blood. The lack of this ability may be due to cardiomyopathy (damaged heart muscle).
- There needs to be enough red blood cells in the bloodstream to carry oxygen. Patients who have anemia can develop shortness of breath, fatigue, and chest pain with activity.
- The lungs need to work so that they deliver enough oxygen to the body. Patients with COPD or emphysema may not be able to extract enough oxygen from the air to supply the body's needs. Most often these patients have shortness of breath but they may also develop angina.
- Certain poisonings including carbon monoxide can prevent oxygen from attaching to red blood cells and cause shortness of breath and chest pain.
If any of these steps fail, the heart muscle may not get enough oxygen and the patient may feel pain or discomfort called angina.
What are the types of angina?
Angina due to a decrease or lack of coronary artery blood flow
Angina is most often caused by narrowing of the coronary arteries because of atherosclerotic heart disease. There may be one or more arteries that are blocked and the amount of pain or other symptom severity is not necessarily related to the number of blood vessels blocked. Usually, there has to be at least a 50% narrowing of a coronary artery to cause symptoms.
Prinzmetal angina describes pain that is caused when a coronary artery goes into spasm temporarily decreasing blood supply to a section of heart muscle.
Microvascular angina describes narrowing of small arteries to cause areas of the heart to have decreased blood flow. The large coronary arteries may be normal.
Syndrome X cardiac disease describes decreased blood flow to the heart muscle with normal coronary arteries not caused by the vasospasm that is seen in Prinzmetal angina. This may be a variant of microvascular angina.
Rare causes may also include abnormalities that occur with the coronary arteries that are not due to ASHD including scarring that can occur from chest radiation, inflammation of the arteries because of underlying illness like systemic lupus erythematosus, scleroderma, and Kawasaki's disease, as well as congenital abnormalities affecting coronary artery anatomy.
Other causes of angina
- Poorly controlled high blood pressure (hypertension) can place significant strain on the heart muscle as it continues to pump blood, causing pain.
- Aortic stenosis describes the narrowed valve that controls blood flow from the left ventricle, the chamber of the heart that pumps blood to the body, into the aorta. If the valve narrows enough, decreased blood flow into the coronary arteries may be the cause of angina.
- Cardiomyopathy describes a variety of conditions where the heart muscle is unable to adequately pump blood to meet the body and the heart's oxygen needs. Ischemic cardiomyopathy, heart muscle that has been damaged by atherosclerotic heart disease, is the most common type of cardiomyopathy.
- Situations exist that can cause the body not to be able to meet the heart's demand for oxygen. These include anemia and poisonings.
- Other circumstances may occur where the heart's oxygen demand is increased and angina occurs. Oxygen demand increases when the heart is asked to pump harder and faster. Examples include tachycardias like atrial fibrillation or atrial flutter that are out of control, fevers, hyperthyroidism, and the stress of major illness, infection, and trauma.
Some causes for angina are multifactorial. For example, a patient with atherosclerotic heart disease may become acutely ill or injured, where a fever or anemia may compound the inability of narrowed blood vessels to deliver oxygen to heart muscle cells. Or a patient who abuses cocaine can increase heart rate plus cause coronary arteries to constrict, leading to angina.
How is angina diagnosed?
The preliminary diagnosis of angina usually is made by the patient's history. The health care professional needs to understand what symptoms the patient is experiencing and may ask similar questions in a variety of ways to gain that understanding. This may be a frustrating process for both patient and professional because the symptoms of angina can range from classic to vague.
Part of the history will be to assess risk factors for heart disease. These include high blood pressure, high cholesterol, diabetes, family history, and smoking. Histories of stroke (cerebrovascular accident or CVA) or peripheral artery disease (PAD) are both risk factors since the mechanism of these diseases, hardening of the arteries or atherosclerosis are the same as for heart disease.
There are other diseases that can cause chest pain, abdominal pain, shortness of breath, sweating, and nausea and vomiting. Questions may be asked to determine whether other possibilities other than angina exist. Pulmonary embolism, pneumonia, aortic aneurysm, gastroesophageal reflux disease (GERD), peptic ulcer disease, and gallbladder disease are bit a few of the potential causes of symptoms other than angina.
Physical examination will help narrow the potential list of diseases but in of itself, will not make the formal diagnosis.
This is the time that the health care professional has to make a clinical decision as to the source of symptoms. If the tentative or provisional diagnosis is angina, a further decision has to be made whether it is stable or unstable.
With stable angina, a defined exercise will bring on the symptoms and rest will make it better. For example, a patient gets chest discomfort after walking 2 miles and it gets better with 5 minutes of rest. The pain pattern is constant and the amount of exercise required to bring on the symptoms has not been getting shorter. Often a patient with known angina will take a nitroglycerin pill to resolve the pain and it does so promptly.
Unstable angina usually happens at rest, wakens the patient at night, or comes on with minimal activity. These are times when the heart muscle is not being asked to work harder and yet angina symptoms may be present. Unstable angina is a potential warning sign of impending heart attack. There may be a transition from stable to unstable and the patient may describe decreasing amounts of exertion needed to bring on the angina symptoms.
Over time, a patient with angina may have their symptoms brought on by less and less activity. This progression needs to be monitored closely by both patient and doctor. The frequency of nitroglycerin use may be a clue that a coronary artery might be getting critically narrow increasing the risk of heart attack.
If angina is the major consideration, then an electrocardiogram (EKG) is usually performed. The electrical signal tracing of the heart can be interpreted to decide if heart muscle is damaged. The initial EKGs most important function is to decide if the patient is in the midst of suffering a heart attack or myocardial infarction (MI). This is a medical emergency.
If the EKG does not show a new heart attack and if the patient has stable symptoms, the next step depends upon the situation. Blood tests may be done to check cardiac enzymes. These are chemicals (troponin, CPK, myoglobin) contained in heart muscle cells that may leak into the bloodstream if the cell is injured. If the chemicals are not detected, then the presumption is that if the pain is due to ASHD, critical narrowing has not caused heart muscle damage. However, the tests need to be done and interpreted based upon the clinical situation.
With a stable EKG, resolved symptoms, and concern still present that the patient has angina, tests to image the heart may be considered. These may include one or more of the following: stress tests, nuclear imaging, echocardiogram, cardiac CT scan, and heart catheterization. The decision as to what test is most appropriate depends upon the patient, their symptoms, underlying health, risk factors, and the level of concern of the health care professional.
What is the treatment for angina?
Treatment for angina depends upon the cause and may include behavior modification, exercise, medication, and surgery.
Should the cause be ASHD, medications may be used to help minimize progression of artery narrowing and plaque buildup. Medications can be also be used to decrease the oxygen requirements of the heart and to allow the heart muscle to function more efficiently.
Aspirin may be recommended to make platelets less sticky to prevent clot formation and prevent heart attack.
Long-acting nitroglycerin medications (Imdur, Nitropaste) may be prescribed to dilate coronary arteries and increase blood flow to the heart muscle. As well, nitroglycerin may be used to abort an episode of angina. In this case it may be taken as a tablet or spray under the tongue.
The best treatment for angina is prevention, especially if the cause is ASHD. Lifelong control of blood pressure, cholesterol, and diabetes will help prevent the development of plaque buildup within arteries not only in the heart but also the brain and peripheral arteries as well. Smoking cessation is mandatory.
Angioplasty and coronary artery bypass surgery
When patients continue to have angina despite maximally tolerated combinations of nitroglycerin medications, beta blockers, and calcium channel blockers, cardiac catheterization with coronary arteriography is indicated. Depending on the location and severity of the disease in the coronary arteries, patients can be referred for balloon angioplasty (percutaneous transluminal coronary angioplasty or PTCA with or without stents) or coronary artery bypass graft surgery (CABG) to increase coronary artery blood flow.
What are other methods are used to evaluate angina?
CT scan calcium scoring is highly accurate in detecting small amounts of calcium in the plaque of coronary arteries. Ultrafast CT scanning is useful in evaluating chest pain in younger patients (men under 40 and women under 50 years old). Since young people do not normally have significant coronary artery plaque, a negative calcium score makes the diagnosis of coronary artery disease unlikely. However, finding calcium by this method is less meaningful in older patients who are likely to have mild plaquing simply from the aging process.
Even though a calcium score is useful in detecting calcium in plaque, it cannot determine whether the calcium-laden plaque actually causes artery narrowing and reduces blood flow. For example, a patient with a densely calcified plaque causing minimal or no artery narrowing will have a strongly positive CT scan, but a normal exercise stress test. In most patients who are suspected of having angina due to coronary artery disease, an exercise stress study is usually the first step in determining whether any plaque is clinically significant. High speed CT scanners can actually detect true coronary artery plaques and lesions similar to coronary angiography.
Magnetic resonance imaging (MRI), using magnetism and radio waves, can be used to image (produce a likeness of) the blood vessels. Larger vessels, such as the carotid arteries in the neck, can be imaged using this technique. Future software and hardware improvements may allow screening of the heart's arteries with magnetic resonance testing.
Can you die from angina?
Prevention offers the best prognosis, but that said, should angina be due to atherosclerotic heart disease, heart function and symptoms may be controlled with lifelong attention to diet, exercise, and appropriately taking medications that may be prescribed.
The purpose in preventing progression of ASHD is to decrease the risk of heart attack. Should one of the coronary arteries become completely blocked, that section of heart muscle may die and be replaced with scar tissue. This leads to a weakened heart that will affect quality of life. Chronically decreased blood flow to heart muscle may not cause a single heart attack but may affect heart function and lead to ischemic cardiomyopathy and again affect lifestyle.
Patients with angina who have had a heart attack and continue to smoke have up to a 50% risk of another heart attack and death.
Patient with Prinzmetal angina and syndrome X have an excellent prognosis with little risk of long term heart damage.
Can angina be prevented?
The risk for atherosclerotic heart disease can be minimized by preventive medicine. Exercise, a healthy diet, and avoiding smoking will decrease the likely of developing atherosclerotic heart disease, stroke, and peripheral artery disease.
A patient should never smoke but heart attack risk begins to decrease shortly after he or she quits smoking.
Understanding that angina and heart disease may not present with symptoms of chest pain may help a patient seek care from a health care professional. This may lead to earlier diagnosis and treatment.
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Mann, D. L., et al. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 10th edition. Saunders. 2014.