Angina (Angina Pectoris)

More than 6 million Americans live with angina. Angina is a condition characterized by chest pain due to a temporary lack of oxygen-rich blood to the heart. The inadequate blood flow is caused by narrowed coronary arteries, which are the blood vessels that supply blood to the heart. A bout of angina is not a heart attack, but it means that you're more likely to have a heart attack than someone who doesn't have angina.


What is Angina?

Angina, also known as angina pectoris, is a painful but temporary heart condition caused primarily by constriction of veins and arteries. Once these blood vessels become tight, the heart's oxygen supply is reduced and the result is pain in the chest, jaw, neck, throat or arms. The pain usually subsides once the blood flow is restored. In essence, angina is the cardiac equivalent of a headache.


The most common cause of angina symptoms is a condition called arteriosclerosis, or a hardening of the arteries. As veins and arteries age, they lose much of their elasticity. When the heart rate increases, as it does during exercise, the oxygenated blood must pass through very narrow blood vessels. The heart receives less of this blood, causing it to feel deprived. The resultant spasming of the heart muscle can cause other muscles and nerves to react in sympathy. Many people feel a tightening sensation in the chest and a temporary anxiety until the pain subsides.


Angina pectoris is not to be confused with a full-blown heart attack, although they share some common symptoms. Most cases of angina are triggered by a definite, stressful event such as overexertion or emotional agitation or exercise. There is a form of angina that can occur without warning, however, but it generally happens during overnight hours. Angina can be a symptom of a more serious cardiac condition, but it usually resolves within a few hours by itself. A heart attack is usually characterized by a heavier and duller pain in the chest, compared to the feelings of pressure in the sternum caused by angina.


The treatment for angina is generally aspirin or groups of drugs known as vasodilators, familiar to those with asthma. Physicians can order a series of stress tests conducted on a treadmill with an ECG machine. Frequent angina can be a sign of more serious cardiac problems, but many sufferers can keep it under control through lifestyle changes and medication. A doctor may recommend that angina patients lose weight, quit smoking and avoid foods with high cholesterol. High blood pressure can also contribute to chronic angina, so many sufferers are urged to take blood pressure medications and find ways to avoid or relieve stress.


This article is not meant to replace the advice of a qualified medical professional. If you experience severe chest pains, consult a doctor immediately for further instructions. The difference between indigestion, angina and a true heart attack cannot be self-diagnosed accurately.


Types of Angina

The three angina types include stable, unstable, and variant, also known as Prinzmetal's angina. The most common types are stable angina and unstable angina. Stable angina generally occurs with physical exertion, but can be improved after rest. Unstable angina is a dangerous condition requiring emergency treatment, and is often a sign that a heart attack could occur soon. Variant angina is a rare form that is caused by a spasm in a coronary artery.


Stable Angina

Stable angina can also be referred to as exertional angina. In stable angina, a coronary artery has been severely narrowed due to the buildup of plaque. Severely narrowed arteries may allow enough blood to reach the heart when the demand for oxygen is low, such as when you are sitting. With exertion, however, like walking up a hill or climbing stairs, the heart works harder and needs more oxygen, which it cannot get. Therefore, a person develops symptoms of angina. With rest, the angina attack symptoms improve.


Unstable Angina

Unstable angina is the second most common type. It is a dangerous condition that requires emergency treatment. Unstable angina occurs more often in older adults and is a sign that a heart attack could occur soon. In fact, 10 to 20 percent of people with unstable angina symptoms will have a heart attack. Unlike stable angina, unstable angina can occur without physical exertion and is not relieved by rest or medicine. In most cases, the condition is caused by blood clots that partially or totally block a coronary artery.


Variant Angina

Variant angina is a rare angina type caused by a spasm in a coronary artery. This spasm causes the walls of the artery to tighten. In turn, this narrows the artery, causing the blood flow to the heart to slow or stop.


Unlike other types of angina that usually occur in someone with coronary artery disease, variant angina may occur in people with or without coronary heart disease.


Symptoms of Angina

The most common symptom of angina is a feeling of pain or discomfort in your chest. The pain can feel tight, dull or heavy and usually passes within a few minutes.


The pain can spread from your chest to your left arm, neck, jaw and back. It usually follows a period of physical activity or emotional stress. In some cases, the pain can also develop after eating a meal or during cold weather. Factors that can cause the symptoms of angina to occur are called angina triggers.


Some people with angina may also experience symptoms of:



The onset of angina symptoms is sometimes known as an angina attack.


The chest pain and discomfort common with angina may be described as pressure, squeezing, fullness or pain in the center of your chest. Some people with angina symptoms describe angina as feeling like a vise is squeezing their chest, or feeling like a heavy weight has been placed on their chest.


The severity, duration and type of angina can vary. It's important to recognize if you have new or changing chest pain. New or different symptoms may signal a more dangerous form of angina (unstable angina) or a heart attack.


Stable angina is the most common form of angina and typically occurs with exertion and goes away with rest. If chest pain is a new symptom for you, it's important to see your doctor to find out what's causing your chest pain and to get proper treatment. If your stable angina gets worse or changes, seek medical attention immediately.


Characteristics of stable angina


Characteristics of unstable angina (a medical emergency)


Dial 911 to request an ambulance if you think that you or someone you are with is experiencing the symptoms of unstable angina.


Characteristics of variant angina (Prinzmetal's angina)


Prinzmetal's angina is rare — only about 2 percent of angina cases are Prinzmetal's angina. This type of angina is caused by a spasm in your heart's arteries that temporarily reduces blood flow.


Angina in women

A woman's angina symptoms can be different from the classic angina symptoms. For example, a woman may have chest pain that feels like a stabbing, pulsating or sharp form of chest pain rather than the more typical vise-like pressure. Women are also more likely to experience symptoms, such as nausea, shortness of breath or abdominal pain. These differences may lead to delays in seeking treatment.


When to see a doctor

If your chest pain lasts longer than a few minutes and doesn't go away when you rest or take your angina medications, it may be a sign you're having a heart attack. Call 911 or emergency medical help. Arrange for transportation. Only drive yourself to the hospital as a last resort.


Causes of Angina

Angina is caused by reduced blood flow to your heart muscle. Your blood carries oxygen, which your heart muscle needs to survive. When your heart muscle isn't getting enough oxygen, it causes a condition called ischemia.


The most common cause of reduced blood flow to your heart muscle is coronary artery disease (CAD). Your heart (coronary) arteries can become narrowed by fatty deposits called plaques. This is called atherosclerosis.


This reduced blood flow is a supply problem — your heart is not getting enough oxygen-rich blood. You may wonder why you don't always have angina if your heart arteries are narrowed due to fatty buildup. This is because during times of low oxygen demand — when you're resting, for example — your heart muscle may be able to get by on the reduced amount of blood flow without triggering angina symptoms. But when you increase the demand for oxygen, such as when you exercise, this can cause angina.






Risk factors

The following risk factors increase your risk of coronary artery disease and angina:











Angina Treatment

There are three aims in treating stable angina. They are:



The last aim is important when deciding on your recommended treatment plan.


If your risk of having a heart attack or stroke is thought to be high because your arteries are significantly narrowed and you have other risk factors, such as high blood pressure or diabetes, a combination of surgery and medication will probably be recommended. Surgery may also be recommended if your symptoms fail to respond to treatment with medication.


If your risk of having heart attack or stroke is thought to be low to moderate, it should be possible to significantly reduce the risk by using a combination of medication and lifestyle changes.


Lifestyle and home remedies

Because heart disease is often the cause of most forms of angina, you can reduce or prevent angina by working on reducing your heart disease risk factors. Making lifestyle changes is the most important step you can take.



Providing immediate relief

Glyceryl trinitrate is a medication that is widely used to provide immediate relief from the symptoms of angina. It can also be used as a preventative measure before undertaking activities that are known to trigger angina.


Glyceryl trinitrate belongs to a group of medication called nitrates. Nitrates work by relaxing and widening the blood vessels that increase the blood supply to the heart.


Glyceryl trinitrate is available in tablet form, which you dissolve under your tongue, or as a spray. The side effects of glyceryl trinitrate include headache and dizziness.


You should avoid drinking alcohol while taking glyceryl trinitrate because it can make the side effects worse. If you experience symptoms of dizziness, avoid driving and operating complex or heavy machinery.


One dose of glyceryl trinitrate usually eases the pain within two to three minutes. If the first dose does not work, a second dose can be taken after five minutes and a third dose after a further five minutes.


You should dial 911 to request an ambulance if the pain persists despite taking three doses of glyceryl trinitrate over a 15 minute period.


Preventing angina attacks

Your doctor or cardiologist (an expert in treating heart conditions) will usually try one medication first to see whether it helps prevent your symptoms. This is known as monotherapy. If one medication is not effective, two medications may be recommended. This is known as combination therapy (see below).


The first medication that is used to try to reduce the frequency of angina attacks is either a medication called a beta-blocker or alternatively a medication called a calcium channel blocker. Exactly which medication you will be prescribed may depend on your current level of health and, in some cases, your personal preference.


Beta-blockers

Beta-blockers make the heart beat slower and with less force. This means that the heart needs less blood and oxygen after exercise, so angina is prevented or occurs less frequently.


Common side effects of beta-blockers include:



Less common side effects of beta-blockers include:



Beta-blockers can also interact with other medicines, causing possible adverse side effects. Therefore, you should check with your doctor or pharmacist before taking other medicines in combination with beta-blockers, including those available over the counter.


Calcium channel blockers

Calcium channel blockers work by relaxing the muscles that make up the walls of your arteries, increasing the blood supply to the heart.


Side effects of calcium channel blockers include:



However, these side effects should pass within a few days once your body gets used to the medicine.


You should never drink grapefruit juice if you are taking calcium channel blockers because they can cause a drop in your blood pressure.


If you are unable to take beta-blockers or calcium channel blockers for medical reasons, or if you find the side effects too unpleasant, your doctor or cardiologist may recommended alternative medication.


Long-acting nitrates

Long-acting nitrates are a similar medication to glyceryl trinitrate, except they are designed for the long-term prevention of symptoms rather than providing short-term relief.


Side effects of long-acting nitrates include headache and a flushed face. Both of these side effects should improve with time.


If you are taking long-acting nitrates, you should not take the anti-erectile dysfunction medication known as sildenafil (Viagra). This is because the combination of the two medications can lead to a dangerous drop in blood pressure.


Ivabradine

Ivabradine is a relatively new type of medication that has a similar effect to beta-blockers in that it slows down the speed of your heart beat.

However, it achieves this effect in a different way to beta-blockers, which means that it can often be used in people who are unable to take beta-blockers for medical reasons, such as those with a lung infection.


A common side effect of ivabradine is that people experience temporary flashes of brightness in their field of vision. If you have this side-effect, it may not be safe for you to drive at night. You should ask your doctor for advice.


Nicorandil

Nicorandil is a potassium channel activator. Potassium channel activators work in a similar way to calcium channel blockers by widening the coronary arteries in order to increase blood flow to the heart.


However, as potassium channel activators achieve this effect in a different way to calcium channel blockers, they can often be used by people who are unable to take calcium channel blockers for medical reasons.


Side effects of nicorandil include:



Ranolazine

Ranolazine works by relaxing the muscles of the heart in order to improve blood flow and prevent angina attacks.


Unlike the other medications that are used to prevent angina attacks, ranolazine does not affects the speed at which the heart beats, so it may be a more suitable alternative treatment for people with heart failure or an abnormal heart rhythm.


Common side effects of ranolazine include:



Combination therapy

If your symptoms fail to respond to one medication, a combination of medications will probably be recommended, which is known as combination therapy.


If your symptoms fail to respond to two medications, you may be referred for surgical treatment (see below).


In some cases, where people are unable or unwilling to have surgery, three different medications are prescribed.


Reducing the risk of heart attack and stroke

Three medications are available to help reduce the risk of a heart attack and stroke in people with angina. They are:


Statins

Statins work by blocking the effects of an enzyme in your liver that is used to make cholesterol. Reducing blood cholesterol levels should prevent further damage to your coronary arteries and should reduce the risk of a heart attack or stroke occurring.


Statins sometimes have mild side effects that can include, constipation, diarrhea and abdominal pain.


Natural forms of cholesterol lowering substances include niacin (vitamin B3) and red yeast rice.


Antiplatelets

Antiplatelets are medications used to reduce the 'stickiness' of platelets to prevent blood clots. Platelets are tiny particles in the blood that help the blood to clot.


Taking antiplatelet medicine reduces your risk of having a heart attack.


Low-dose aspirin (usually 75mg daily) is the preferred antiplatelet medicine. If you are allergic to aspirin, or you are unable to take it due to having another health condition that may be aggravated by it, such as stomach ulcer, alternative antiplatelet medications are available.


Angiotensin-converting enzyme (ACE) inhibitors

Angiotensin-converting enzyme (ACE) inhibitors are medicines that can be used to reduce your blood pressure.


ACE inhibitors block the activity of a hormone called angiotensin II, which narrows blood vessels. As well as stopping the heart working so hard, ACE inhibitors improve the flow of blood around the body.


ACE inhibitors have been known to reduce the supply of blood to the kidneys, which can reduce their efficiency. Therefore, blood and urine tests may be carried out before you start taking ACE inhibitors to make sure there are no pre-existing problems with your kidneys.


Annual blood and urine tests may also be required if you continue to use ACE inhibitors.


Side effects of ACE inhibitors include, dizziness tiredness or weakness and a persistent, dry cough, although these should pass within a few days.


You should check with your doctor or pharmacist before taking any other medication in combination with ACE inhibitors as they can cause side effects.


Surgery

Surgery is usually recommended if your angina symptoms fail to respond to medication. However you will probably need to continue taking some medication after having surgery.


There are two main types of surgery that can be used to treat angina are:




CABG or PCI?

In some circumstances it may not be possible to choose whether you have a CABG or a PCI. For example, PCI may not be suitable for people whose blood vessels have an unusual structure because it can make the PCI technique particularly challenging.


Both PCI and CAGB are broadly similar in their effectiveness in treating angina and preventing fatal complications in the long-term, although each technique has its own set of pros and cons.


As PCI does not involve making major incisions in the body, the recovery time from surgery is much quicker and it involves much less post-operative pain.


One main disadvantage of PCI is that there is a higher risk of the unblocked section of artery becoming blocked again which would require further surgery to treat. The most recent data shows that further surgery is required in around 1 in 25 cases.


CABG is usually the preferred surgical option for people who:



Research indicates that using the CABG technique in such circumstances is more likely to prolong lifespan than using the PCI technique. There is also recent evidence that people who have had a CABG usually report a slightly better quality of life in the long-term.


The disadvantage of CABG is that it causes more post-operative pain than PCI and it also has a longer recovery time which is usually around 12 weeks compared to about one to two weeks for PCI.


Unstable angina

If you have unstable angina (where symptoms develop rapidly and persist even at rest), upon being admitted to hospital you will be given medication to prevent blood clots developing and reduce your risk of having a heart attack or stroke.


This will usually be aspirin (used for its blood thinning abilities rather than as a pain killer) unless there is a reason you are unable to take aspirin, such as having a history of liver disease.


You will probably also be prescribed another blood-thinning medication called clopidogrel, which you may need to take for at least 12 months (if you are unable to take aspirin you will just be prescribed clopidogrel).


You may also be given an injection of an additional blood thinning medication such as fondaparinux or heparin.


It is likely that you will then have a series of tests to assess your risk of having a heart attack in the future.


If the risk is moderately high, a coronary angiography may be carried out to assess the size and location of the blockage in your coronary artery. If the blockage is significant, a CABG or a PCI can be performed to widen the artery.