What is angina?
Angina is a condition resulting from a disease of the coronary arteries which causes a decreased blood flow to the heart muscle and presents with chest pain or discomfort as a primary symptom.
Is angina condition a medical emergency?
Angina is a medical emergency and requires immediate medical attention in the following situations:
- The chest pain lasts longer than a few minutes
- The chest pain does not subside on taking rest or angina medications
- It is the first time that the chest pain or discomfort is appearing
- If a previously diagnosed angina is worsening
Types of angina
There are a few variants of angina and they are:
- Stable angina or effort angina: This is the classic form of angina that is brought on by activity, lasts for a few minutes, and subsides with rest and sublingual nitroglycerin.
- Unstable angina or crescendo angina: It is seen as a type of Acute Coronary Syndrome, and it may have the following features:
- It is occurring as a new event or for the first time
- The symptoms occur at rest and are prolonged, and lasting for more than 10 minutes
- Previous symptoms of stable angina begin to worsen with the symptoms becoming more frequent, more severe and lasting longer than before
- Cardiac X syndrome or microvascular angina: It is seen even though there are no significant blockages of the major arteries supplying the heart, but instead is due to conditions affecting the smaller branches of these arteries.
- Prinzmetal angina: It is caused due to spasm and subsequent narrowing of the arteries, and there is no significant blockage of the major arteries supplying the heart muscle.
- Angina decubitus: Is another variant of angina that is seen to occur at night when the patient is sleeping or lying down.
Causes of angina
Angina is caused primarily due to reduced blood flow and a resulting failure to meet the oxygen demand of the heart muscle and is usually due to a blockage of the arteries that supply blood to the heart, although sometimes in women the cause of angina is usually not due to a blockage of the arteries.
The causes of angina include:
- Atherosclerosis or fat deposits and around 50% blockage of the arteries supplying blood to the heart
- Spasm of the arteries supplying blood to the heart
- Systemic diseases affecting blood vessels such as Scleroderma, Lupus, Kawasaki disease, polyarteritis nodosa, Takayasu arteritis, etc.
- Abnormalities of the heart that are present at the time of birth such as coronary artery fistula or aneurysm, coronary artery ectasia, etc.
- Coronary artery fibrosis after radiotherapy to the chest
- Coronary intimal fibrosis after cardiac transplantation
- Severe anemia with hemoglobin less than 8 g/dl
- Emotional stress
- Left ventricular hypertrophy
- Irregular heart rhythms such as bradyarrhythmias (slow) or tachyarrhythmias (fast)
- Valvular heart disease such as aortic stenosis
- Esophageal disease and Gastroesophageal reflux disease (GERD)
Risk factors for angina
The risk factors for angina are many and include the risk factors for coronary artery disease as well. They are:
- Family history of coronary artery disease
- High levels of cholesterol and fats in the blood
- Physical inactivity
- Kidney disease
- Severe emotional stress
Some activities that can trigger angina are:
- Walking fast outside in cold, or humid weather
- Moving quickly while carrying a heavy load
- Engaging in strenuous activity after a heavy meal
- Work-related stress
- Social anxiety while speaking in public
- Engaging in sexual activity
- Emotional stress from being worried, angry, or tense
Signs & symptoms of angina
The symptoms and signs of angina include:
- Chest pain or discomfort, which is expressed as pressure, squeezing, heaviness, choking, burning, fullness. The pain is usually present in the epigastrium, which is the region just above the stomach. The pain usually lasts for a few minutes and is relieved by rest or taking sublingual nitroglycerin.
- Additionally, there may be a pain in the arms, neck, jaw, shoulder or back
- The pain does not increase or decrease with cough, breathing, or change in position
- Difficulty breathing
In women, the symptoms may be slightly different and may include:
- Pain which is described as a stabbing pain instead of as a pressure or tightness
- Abdominal pain
- Additionally, the pain may be present in the neck, back or jaw
- Breathing difficulties
The following investigations may be done to establish a diagnosis of angina:
- Electrocardiogram (ECG): To evaluate the electrical activity of the heart
- Echocardiogram and stress echocardiography: Ultrasound imaging of the heart is done to evaluate the functioning of the heart as well as to identify any areas of damage due to reduced blood flow
- Stress tests: To assess the capability and the functioning of the heart when performing strenuous activity
- Nuclear stress test or myocardial perfusion imaging: Radioactive isotopes are used to assess and measure blood flow to the heart when performing strenuous activity
- CT scan: Either a coronary CT scan or a Coronary Artery Calcium uptake scan may be done to assess the extent of atherosclerosis and heart muscle damage
- MRI: Cardiac Magnetic Resonance Imaging is done for a detailed evaluation of the blood vessels supplying to the heart
- Coronary Angiography: To evaluate the blood vessels supplying to the heart. It may be done as an X-ray angiography or as CT angiography
- Blood tests: To detect the presence of cardiac markers such as troponin which are elevated in the event of a heart attack
Diagnosis of angina
A diagnosis of angina is established based on clinical evaluation and the results of the investigations performed. ECG findings of ST-segment depression of more than 1 mm as seen during exercise or stress testing is considered diagnostic of Angina when present with other clinical symptoms and signs.
Course & stages
Angina may be quantified based on the severity of symptoms as follows:
- Class I: No limitation of physical activity or only very strenuous and prolonged activity causes symptoms
- Class II: Slight limitation of physical activity or ordinary activity does not cause symptoms and they are present only on severe physical activity
- Class III: Moderate limitation of physical activity (comfortable at rest), or symptoms with everyday physical activities
- Class IV: Severe limitation with the inability to perform any physical activity or symptoms present with any physical activity and symptoms may be present even at rest
Angina treatment options
The management of angina depends on the severity of the condition, and it includes lifestyle modifications, medication, and surgical intervention is required. Treatment aims to reduce the severity of the symptoms so that the individual can lead a normal life without limitations, and also prevent the possibility of a future heart attack.
A. Medical management
Medical management through the administration of drugs is considered when lifestyle changes have not been successful in managing the symptoms of mild angina, or if the severity of the condition at the time of diagnosis requires it.
The medications that may be prescribed either singly or in combination include:
- Nitrates: Such as sublingual nitroglycerin to widen the blood vessels
- Antiplatelet agents: Such as aspirin, clopidogrel are used to prevent the formation of blood clots
- Beta-adrenergic blocking agents: To lower blood pressure and to widen the blood vessels
- Calcium channel blockers: Such as amlodipine, verapamil, are used to widen the blood vessels and reduce the workload on the heart and are usually indicated when beta-blockers are not effective
- Angiotensin-converting enzyme (ACE) inhibitors: Such as ramipril are used to widen the blood vessels
- Anti-ischemic agents: Such as ranolazine are used when there is long-standing angina that is not responding to other medications
B. Interventional including surgery and indications for surgery
Interventional procedures and surgery for revascularization may be required in severe cases of angina where there is a greater risk of a future heart attack such as:
- More than 50% block in the left main artery
- 2-3 vessels are blocked
- Left ventricle function is very poor with an ejection fraction less than 45%
- Poor response and severe symptoms despite maximum medical therapy
The interventional and surgical procedures include:
- Angioplasty and Stenting or PCI: Percutaneous coronary intervention or angioplasty is a minimally invasive procedure in which a balloon is guided with the help of a catheter to widen or open up the blocked arteries, and a stent, which is a tiny metal tube, is kept in place to prevent the walls of the artery from collapsing.
- Coronary Artery Bypass Grafting: Is a surgical procedure in which an artery or vein from another part of the body is used as a graft to bypass the blocked coronary arteries. It is usually done in the management of triple vessel disease.
C. Role of diet/exercise/lifestyle changes/preventive measures
Lifestyle modifications, diet, and exercise play an important role in the prevention and management of angina. These include:
- Cessation of smoking and avoiding second-hand smoke
- Reducing excess weight if there is obesity
- Avoiding heavy meals, and eating a balanced diet low in saturated fats that include vegetables, fruits, whole grams
- Regular physical activity or exercise as advised by a medical specialist
- Keeping diabetes, high blood pressure, and serum cholesterol and lipids under control
- Keeping emotional stress under control or seeking help from professionals to deal with it
Complications of angina
The complication of angina include:
- Limitation of physical and day to day activities
- Unstable angina
- Heart attack or Myocardial Infarction
The prognosis of angina depends on the severity, lifestyle modifications, and a few prognostic indicators as follows:
- Reduced Left Ventricle function with a low ejection fraction is associated with a poor prognosis.
- Severe obstruction of the left main and the left anterior descending arteries is associated with a poor prognosis.
- Prognosis is poor if a greater number of arteries are involved.
- ECG findings of ST-segment depression of more than 2mm or ST-segment depression that persists for more than 5 minutes is indicative of a higher risk of serious cardiac events.
- Individuals who continue to smoke even after angina or a heart attack have a very poor prognosis.
- The long term prognosis for Prinzmetal angina and cardiac X syndrome is very good.
When to contact the doctor or hospital/how to identify the emergency or complications?
It is advisable to get immediate medical attention in the following situations:
- The symptoms of angina are coming on for the very first time
- The symptoms of a previously diagnosed stable angina are becoming more severe, more frequent, and more prolonged
- The symptoms of a previously diagnosed stable angina are lasting longer, or are not relieved by rest or angina medication
Indications for hospitalization if required
Hospitalization may be required for the initial stabilization of the individual, for conducting investigations, or for performing interventional procedures if required, especially if the symptoms are severe or are coming on for the first time.
Suggested clinical specialist/departments to consult for this condition
The emergency department will be the first medical department to attend to this condition and will be followed up and treated by the cardiology department.