What is angina?
Myocardial ischemia occurs when blood flow to the cardiac muscle is blocked. This congested state can produce a clinical symptom of tightness and pressure pain in the chest area; this symptom is known as angina. The discomfort is typically exerted by stress, such as exercise, and the symptom manifests as the oxygen demand surpasses supply, Disproportions of oxygen supply to the heart appear when arteries are narrowed due to various diseases such as atherosclerosis( hardening of the arteries caused by a buildup of plaque) and thrombosis (when a blood clot forms either in an artery or vein).1
Causes and risk factors
The cause of angina is very complex as there are many contributing causes for the myocardial oxygen demands to increase much higher than the available supply. The narrowing of coronary arteries in an individual is generally a major sign of atherosclerosis; however, it can also occur due to Coronary artery spasm, embolism or thrombosis. Furthermore, the cardiac workload also increases with other disorders like aortic stenosis, hypertension and hypertrophic cardiomyopathy, which all exacerbate angina.2 Such mechanisms disrupt the normal endothelial function of coronary arteries, triggering an inflammatory healing process which would allow fatty deposits or fibrotic plaques to attach and narrow the vessel. Factors contributing to this process include stress, hypertension, high cholesterol, pathogens and immune disorders.1 There are common triggers for patients who experience pain from angina, mainly stimulation of physical activity, emotional stress, experiencing cold weather and eating a big meal.
Important risk factors that develop angina:
- Physical or emotional stress
- Inappropriate overuse of alcohol or recreational drugs
- Low physical activity
- Unhealthy diet high in fat, salt and sugar
- High cholesterol or triglyceride levels
- Overweight or obesity
- Other chronic diseases
- Increasing age (45+ for males & 55+ for females)
Types of angina
- Stable angina
- Unstable angina
- Variant angina
- Microvascular angina
Clinically, there are four different types of angina. Stable angina is the most prevalent type in patients; it manifests when there is an intense workload on the heart, but the pain should go away at rest. The incidence would commonly last no longer than 5 minutes if rested or medication is administered after the event. Whereas in unstable angina, the signs appear differently than in a normal angina episode, as they could also appear during a rested state with more forceful distress to the chest for a longer duration. Variant angina, which is also known as vasospastic angina,, is very infrequent in patients; it appears sometimes at night during sleep or rest. In this incident, the coronary artery with the oxygenated blood malfunctions and goes into a spasm, which tightens the blood vessels. The final type of angina is called Microvascular angina, which generally transpires under a form of physical pressure, such as exercise or anxiety; the associated pain is often produced due to spasms in very tiny coronary arteries.3
Most cases of angina are presented as versions of chest discomfort, with a variety of other symptoms depending on each individual’s case. The pain itself can be described as a form of heavy pressure or tightness within the chest, especially underneath the sternum, although there is not a specific location, rather just all over the chest. The chest pain is described by the patient as a burning, fullness, pressure or squeezing sensation. Often the associated pain would also radiate to other nearby parts of the body, mainly in the left arm, back, jaw, neck and stomach. The discomfort should not extend to cover the ears or under the umbilicus. Both genders experience similar symptoms of angina; however, females tend to also experience nausea and dizziness. Other common symptoms experienced and reported by patients include sweating, fatigue, nausea, shortness of breath and dizziness.
Angina time duration
(Also discuss different time durations for types of angina.)
A typical episode of angina would usually last between 3 to 5 minutes, although it is possible for them to last longer and up to 30 minutes. But heart attacks generally last more than 30 minutes. For stable angina, most cases last around 5 minutes and rarely do individuals have an episode longer than 15 minutes, as they are relieved easily. Since the discomfort can get worse very easily with unstable angina, it often lasts much longer than stable angina, averaging 20 minutes for patients. It is very common for variant angina to spread to other parts; hence it might last anytime between a few minutes to 30 minutes. Treatment for microvascular angina takes longer, and so it is considered more chronic; therefore, it can last longer than stable angina, maybe even more than 30 minutes.
It is essential for physicians to properly examine the medical history of the patient as well as any screening tools. As they need to differentiate between the cardiac and non-cardiac associated symptoms so that it is easier to follow a differential diagnosis. Important questions asked would include the quality, location, length and severity of the chest discomfort experienced.1 An electrogram can be obtained to measure the activity of an ischemic state or look for past infarctions. Due to angina resolving quite quickly, electrograms cannot be performed during an attack. The test would display a normal LV function in a third of patients if done in between angina attacks. The majority of patients would show random ST-segment and T-wave abnormalities, indicating previous cardiac infractions. A very common method to diagnose coronary artery disease is through coronary angiography; it aids doctors in evaluating and locating the severity of the revascularisation process within a patient. Doctors would consider the reduction of the vessel lumen to be clinically significant if over 70% of the diameter has been decreased for proper angina episodes to occur. To observe the vasculature of the coronary artery, an intravascular ultrasound would display an image via the usage of a probe and catheter, which tends to provide more information for proper assessment of each angina case presented. Furthermore, imaging studies done on patients can reveal important evidence regarding a person’s coronary arteries. A specific version of computerised tomography (CT) scan is called the Multidetector row CT (MDRCT), which is non-invasive and able to specifically pinpoint coronary stenosis. Although this test involves a lot of radiation, it is not considered appropriate for patients with a heart rate over 65 beats per minute and more vulnerable individuals, like pregnant women. A cardiac MRI could also be used in some cases; however, it is not as valuable when compared to other diagnostic tools.2 In addition to that, it is always to complete the general screening for patients presented to an emergency room with abnormal cardiac symptoms, and these tests typically include a complete blood count, inclusive of metabolic lipid and troponin level measurements. These tests are a key element to help physicians rule out other explanations for the manifestation of such pain or discomfort.
The main aim of a treatment option for angina is to relieve and stop the experienced symptoms, which can be achieved via a variety of factors. A pharmacological approach can be taken in which different classes of medication actively work to prevent discomfort to the patient. Aspirin and other antiplatelet drugs restrain the aggregation of platelets in blood vessels; they can reduce the risk of developing an ischemic episode, but not all patients can take the drug depending on individual differences in genetics and angina cases.2 Using an angiotensin receptor blocker helps to decrease blood pressure in high-risk patients, which controls the individual’s cardiovascular workload and reduces the threat of angina and other cardiovascular diseases.1 In addition to that, beta-blockers are known to show a reduction in heart rate and blood pressure, which reduces the overall myocardial oxygen consumption and consequently alleviates anginal effects. An advantage of these drugs is that many patients can tolerate them, and they are widely accessible and effective. Furthermore, nitrates that are long-lasting aid to relax the smooth muscle of coronary arteries, which reduces the preload effect on the heart and again decreases the oxygen demand. Oral nitrates are usually effective by 1 or 2 hours after administration; their effects would also last for up to 6 hours. Another FDA-approved drug used for angina is called ranolazine; it is a sodium channel blocker that is effective in relieving the associated symptoms.2
The prognosis of each angina case would depend on the aetiology of the angina symptoms as well as other factors like age, cardiovascular function, lifestyle and general medical health. A significant complication of angina is the high chance of developing acute coronary syndrome, which is a range of clinical conditions related to an obstruction of blood flow to the heart, including a heart attack.
An important long-term approach is to tackle a patient’s lifestyle to either actively eliminate the disease or reduce the discomfort received; there are qualified individuals such as nutritionists, therapists and trainers who can direct a person to a healthier lifestyle path. The most important change is if the patient is a smoker, they should break the habit, as tobacco cessation will show the biggest reduction in anginal risk. Secondly, the patient must control their blood cholesterol levels, as high cholesterol directly correlates with an increase of fatty deposits in arteries. Therefore, a healthy diet and a good exercise regimen can moderate the triglyceride content consumed and stored in the body; the same can also be said when controlling diabetes mellitus. Such healthy modifications are very important as obesity is considered the second leading modifiable cause of mortality.1
When to get medical help
By spreading the correct scientific information regarding angina and cardiovascular health to the general public, individuals will grasp the importance of a healthy lifestyle as well as when to seek immediate medical attention during an angina episode. It is essential to visit a physician if you have not yet been diagnosed with angina but have severe chest pain that manifests during exertion and stops at rest. On the other hand, if you have been diagnosed but the discomfort has increased significantly, then it is vital to reach out to your doctor as soon as possible.3
To conclude, the disease angina is a clinical syndrome consisting of localised discomfort and pressure in the chest area and often other close body parts. The duration of the discomfort could last anywhere from a few minutes to over 15 minutes, depending on the patient. There are four distinct types of angina: There are several types of angina, including stable angina, unstable angina, vasospastic angina and microvascular angina. The event is commonly triggered by a form of physical or psychological stress, which increases the cardiac oxygen demand, but due to obstructed coronary arteries, the blood flow is compromised. The uncomfortable symptoms are typically relieved by rest, stopping the triggering event or taking medications. The disease can be diagnosed by a variety of diagnostic tools, including imaging, electrocardiography, angiography and laboratory testing. Treatment for a patient depends on the severity of their condition, but it is usually via an interdisciplinary approach of short-term medications like antiplatelet drugs, nitrates, beta-blockers and many more, as well as long-term lifestyle modifications to prevent further episodes in the future.
- Gillen C, Goyal A. Stable Angina. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 [cited 2023 Oct 12]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK559016/.
- Angina pectoris - cardiovascular disorders. MSD Manual Professional Edition [Internet]. [cited 2023 Oct 12]. Available from: https://www.msdmanuals.com/en-gb/professional/cardiovascular-disorders/coronary-artery-disease/angina-pectoris.
- Angina - Causes, symptoms & treatments. British Heart Foundation [Internet]. [cited 2023 Oct 12]. Available from: https://www.bhf.org.uk/informationsupport/conditions/angina