Angina | |
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Other names | Stenocardia, angina pectoris |
Illustration depicting angina | |
Pronunciation | |
Specialty | Cardiology |
Complications | Myocardial infarction, unstable angina |
Angina, also known as angina pectoris, is chest pain or pressure, usually caused by insufficient blood flow to the heart muscle (myocardium). [2] It is most commonly a symptom of coronary artery disease. [2]
Angina is typically the result of partial obstruction or spasm of the arteries that supply blood to the heart muscle. [3] The main mechanism of coronary artery obstruction is atherosclerosis as part of coronary artery disease. Other causes of angina include abnormal heart rhythms, heart failure and, less commonly, anemia. [4] The term derives from Latin angere 'to strangle'and pectus 'chest', and can therefore be translated as "a strangling feeling in the chest".
An urgent medical assessment is suggested to rule out serious medical conditions. [5] There is a relationship between severity of angina and degree of oxygen deprivation in the heart muscle. However, the severity of angina does not always match the degree of oxygen deprivation to the heart or the risk of a heart attack (myocardial infarction). Some people may experience severe pain even though there is little risk of a heart attack whilst others may have a heart attack and experience little or no pain. [6] [7] In some cases, angina can be quite severe. Worsening angina attacks, sudden-onset angina at rest, and angina lasting more than 15 minutes are symptoms of unstable angina (usually grouped with similar conditions as the acute coronary syndrome). As these may precede a heart attack, they require urgent medical attention and are, in general, treated similarly to heart attacks. [8]
In the early 20th century, severe angina was seen as a sign of impending death. [9] However, modern medical therapies have improved the outlook substantially. Middle-age patients who experience moderate to severe angina (grading by classes II, III, and IV) have a five-year survival rate of approximately 92%. [10]
Also known as 'effort angina', this refers to the classic type of angina related to myocardial ischemia. A typical presentation of stable angina is that of chest discomfort and associated symptoms precipitated by some activity (running, walking, etc.) with minimal or non-existent symptoms at rest or after administration of sublingual nitroglycerin. [11] Symptoms typically diminish several minutes after activity and recur when activity resumes. In this way, stable angina may be thought of as being similar to intermittent claudication symptoms. Other recognized precipitants of stable angina include cold weather, heavy meals, and emotional stress.
Unstable angina (UA) (also "crescendo angina"; this is a form of acute coronary syndrome) is defined as angina pectoris that changes or worsens or begins suddenly at rest. [12] Unstable angina is a medical emergency and requires urgent medical treatment from a doctor. [5]
It has at least one of these three features: [13]
UA may occur often unpredictably and even at rest, which may be a serious indicator of an impending heart attack. The primary factor differentiating unstable angina from stable angina (other than symptoms) is the underlying pathophysiology of the atherosclerosis. The pathophysiology of unstable angina is the reduction of coronary blood flow due to transient platelet aggregation on apparently normal endothelium, coronary artery spasms, or coronary thrombosis. [14] [15]
The process starts with atherosclerosis, progresses through inflammation to yield an active unstable plaque, which undergoes thrombosis and results in acute myocardial ischemia, which, if not reversed, results in cell necrosis (infarction). [15] Studies show that 64% of all unstable anginas occur between 22:00 and 08:00 when patients are at rest. [15] [16]
In stable angina, the developing atheroma (a fatty plaque) is protected with a fibrous cap. This cap may rupture in unstable angina, allowing blood clots to precipitate and further decrease the area of the coronary vessel's lumen or the interior open space within an artery. This explains why, in many cases, unstable angina develops independently of activity. [15]
Microvascular angina, also known as cardiac syndrome X, is characterized by angina-like chest pain, in the context of normal epicardial coronary arteries (the largest vessels on the surface of the heart, prior to significant branching) on angiography. The original definition of cardiac syndrome X also mandated that ischemic changes on exercise (despite normal coronary arteries) were displayed, as shown on cardiac stress tests. [17] The primary cause of microvascular angina is unknown, but factors apparently involved are endothelial dysfunction and reduced flow (perhaps due to spasm) in the tiny "resistance" blood vessels of the heart. [18] Since microvascular angina is not characterized by major arterial blockages, it is harder to recognize and diagnose. [19] [20] [21]
Microvascular angina was previously considered a rather benign condition, but more recent data has changed this attitude. Studies, including the Women's Ischemia Syndrome Evaluation (WISE), suggest that microvascular angina is part of the pathophysiology of ischemic heart disease, perhaps explaining the higher rates of angina in females than in males, as well as their predilection towards ischemia and acute coronary syndromes in the absence of obstructive coronary artery disease. [22]
This section needs additional citations for verification .(June 2013) |
Angina pectoris can be quite painful, but many patients with angina complain of chest discomfort rather than actual pain: the discomfort is usually described as a pressure, heaviness, tightness, squeezing, burning, or choking sensation. Apart from chest discomfort, anginal pains may also be experienced in the epigastrium (upper central abdomen), back, neck area, jaw, or shoulders. This is explained by the concept of referred pain and is because the spinal level that receives visceral sensation from the heart simultaneously receives cutaneous sensation from parts of the skin specified by that spinal nerve's dermatome, without an ability to discriminate the two. Typical locations for referred pain are arms (often inner left arm), shoulders, and neck into the jaw. Angina is typically precipitated by exertion or emotional stress. It is exacerbated by having a full stomach and by cold temperatures. Pain may be accompanied by breathlessness, sweating, and nausea in some cases. In this case, the pulse rate and the blood pressure increases. Chest pain lasting only a few seconds is normally not angina (such as precordial catch syndrome).
Myocardial ischemia comes about when the myocardium (the heart muscle) receives insufficient blood and oxygen to function normally either because of increased oxygen demand by the myocardium or because of decreased supply to the myocardium. This inadequate perfusion of blood and the resulting reduced delivery of oxygen and nutrients are directly correlated to blocked or narrowed blood vessels.
Some experience "autonomic symptoms" (related to increased activity of the autonomic nervous system) such as nausea, vomiting, and pallor.
Major risk factors for angina include cigarette smoking, diabetes, high cholesterol, high blood pressure, sedentary lifestyle, and family history of premature heart disease.
A variant form of angina—Prinzmetal's angina—occurs in patients with normal coronary arteries or insignificant atherosclerosis. It is believed caused by spasms of the artery. It occurs more in younger women. [23]
Coital angina, also known as angina d'amour, is angina subsequent to sexual intercourse. [24] It is generally rare, except in patients with severe coronary artery disease. [24]
Routine counseling of adults by physicians to advise them to improve their diet and increase their physical activity has, in general, been found to induce only small changes in actual behavior. Therefore, as of 2012, The U.S. Preventive Services Task Force does not recommend routine lifestyle counseling of all patients without known cardiovascular disease, hypertension, hyperlipidemia, or diabetes, and instead recommends selectively counseling only those patients who seem most ready to make lifestyle changes and using available time with other patients to explore other types of intervention that would be more likely to have a preventative impact. [26]
One study found that smokers with coronary artery disease had a significantly increased level of sympathetic nerve activity when compared to those without. This is in addition to increases in blood pressure, heart rate, and peripheral vascular resistance associated with nicotine, which may lead to recurrent angina attacks. In addition, the Centers for Disease Control and Prevention (CDC) reports that the risk of CHD (Coronary heart disease), stroke, and PVD (Peripheral vascular disease) is reduced within 1–2 years of smoking cessation. In another study, it was found that, after one year, the prevalence of angina in smokingmales under 60 after an initial attack was 40% less in those having quit smoking compared to those that continued. Studies have found that there are short-term and long-term benefits to smoking cessation. [28] [29] [30] [31]
Myocardial ischemia can result from:
Atherosclerosis is the most common cause of stenosis (narrowing of the blood vessels) of the heart's arteries and, hence, angina pectoris. Some people with chest pain have normal or minimal narrowing of heart arteries; in these patients, vasospasm is a more likely cause for the pain, sometimes in the context of Prinzmetal's angina and syndrome X.
Myocardial ischemia also can be the result of factors affecting blood composition, such as the reduced oxygen-carrying capacity of blood, as seen with severe anemia (low number of red blood cells), or long-term smoking.
Angina results when there is an imbalance between the heart's oxygen demand and supply. This imbalance can result from an increase in demand (e.g., during exercise) without a proportional increase in supply (e.g., due to obstruction or atherosclerosis of the coronary arteries).
However, the pathophysiology of angina in females varies significantly as compared to males. [38] Non-obstructive coronary disease is more common in females. [39] [40]
Angina should be suspected in people presenting tight, dull, or heavy chest discomfort that is: [41]
Some people present with atypical symptoms, including breathlessness, nausea, or epigastric discomfort, or burning. These atypical symptoms are particularly likely in older people, women, and those with diabetes. [41]
Anginal pain is not usually sharp or stabbing or influenced by respiration. Antacids and simple analgesics do not usually relieve the pain. If chest discomfort (of whatever site) is precipitated by exertion, relieved by rest, and relieved by glyceryl trinitrate, the likelihood of angina is increased. [41]
In angina patients momentarily not feeling any chest pain, an electrocardiogram (ECG) is typically normal unless there have been other cardiac problems in the past. During periods of pain, depression, or elevation of the ST segment may be observed. To elicit these changes, an exercise ECG test ("treadmill test") may be performed, during which the patient exercises to his/her maximum ability before fatigue, breathlessness, or pain intervenes; if characteristic ECG changes are documented (typically more than 1 mm of flat or downsloping ST depression), the test is considered diagnostic for angina. Even constant monitoring of the blood pressure and the pulse rate can lead to some conclusions regarding angina. The exercise test is also useful in looking for other markers of myocardial ischemia: blood pressure response (or lack thereof, in particular, a drop in systolic blood pressure), dysrhythmia, and chronotropic response. Other alternatives to a standard exercise test include a thallium scintigram or sestamibi scintigram (in patients unable to exercise enough for the treadmill tests, e.g., due to asthma or arthritis or in whom the ECG is too abnormal at rest) or stress echocardiography.
In patients in whom such noninvasive testing is diagnostic, a coronary angiogram is typically performed to identify the nature of the coronary lesion, and whether this would be a candidate for angioplasty, coronary artery bypass graft (CABG), treatment only with medication, or other treatments. In hospitalized patients with unstable angina (or the newer term of "high-risk acute coronary syndromes"), those with resting ischaemic ECG changes or those with raised cardiac enzymes such as troponin may undergo coronary angiography directly.
Angina pectoris occurs as a result of coronary blood flow insufficiency in the face of increased oxygen demand. The principal goal in the prevention and relief of angina is to limit the oxygen requirement of the heart so it can meet the inadequate oxygen supply derived through the blood supplied from the stenosed or constricted arteries. The main goals of treatment in angina pectoris are relief of symptoms, slowing progression of the disease, and reduction of future events, especially heart attacks and death. Beta blockers (e.g., carvedilol, metoprolol, propranolol) have a large body of evidence in morbidity and mortality benefits (fewer symptoms, less disability, and longer life) and short-acting nitroglycerin medications have been used since 1879 for symptomatic relief of angina. [42] There are differing course of treatments for the patient depending on the type of angina the patient has. However, this second can provide a brief overview of the types of medications provided for angina and the purpose by which they are prescribed.
Beta blockers, specifically B1 adrenergic blockers without intrinsic sympathomimetic activity, are preferred for angina treatment, out of B1 selective and non-selective as well as B1 ISA agents. B1 blockers are cardioselective blocking agents (such as nevibolol, atenolol, metoprolol, bisoprolol, etc.) which result in blocking cAMP in the heart muscle cells. cAMP, which plays a vital role in phosphorylating the ryanodine receptor and LTCC, will usually increase Ca+2 levels in the heart muscle cells, blocking contraction. Therefore, B1 blockade decreases the HR and contraction of the heart muscle, making it demand less oxygen. An important thing to note is that the B1 cardioselective blockers are cardioselective and not cardio-specific. This means that if the beta-adrenergic antagonist is prescribed in higher doses, it can lose the selectivity aspect and begin causing hypertension from B2 adrenergic stimulation of smooth muscle cells. This is why in therapy for patients with angina, the vasodilatory organonitrates complement the use of B-blockers when prescribed the use of angina. The preference for Beta-1 cardioselective blockers is for B1 cardioselective blockers without instrinsic sympathetic activity. Beta blockers with intrinsic sympathetic activity will still do the beta blockade of the heart muscle cells and have a decreased ionotrophic and chronotropic effect, but this effect will be to a lesser extent than if the beta blocker did not have the instrinsic sympathetic activity. A common beta-blocker with ISA prescribed for the treatment of angina is Acebutolol.
Non-selective beta-adrenergic antagonists will yield the same action on B1 receptors, however will also act on B2 receptors. These medications, such as Propranolol and Nadolol, act on B1 receptors on smooth muscle cells as well. B1 blockade occurs in the smooth muscle cells. Specifically cAMP is responsible for inhibiting Myosin Light Kinase, the enzyme responsible for acting on Actin-Myosin. The inhibition of B1 will result in decreased levels of cAMP which will lead to increased levels of Myosin Light Chain Kinase in the smooth muscle cells, the enzyme responsible for acting on Actin-Myosin and leading to contraction of the smooth muscle cell. This increased contraction of the smooth muscle cell from B1 blockade is not desirable since it explains the hypertension that may arise with patients taking that medication.
Calcium channel blockers act to decrease the heart's workload, and thus its requirement for oxygen by blocking the calcium channels of the heart muscle cell. With decreased intracellular calcium, the calcium-troponin complex does not form in the heart muscle cell and it does not contract, therefore reducing the need for oxygen.
The other class of medication that can be used to treat angina are the organic nitrates. Organic nitrates are used extensively to treat angina. They improve coronary blood flow of the coronary arteries (arteries which supply blood to the heart muscle) by reversing and preventing vasospasm, which increases the blood flow to the heart, improving perfusion and oxygen delivery to the heart associated with the pain of angina. These drugs also reduce systemic vascular resistance, of both veins and arteries but the veins to a greater extent. The decrease in the resistance of the arteries and veins decreases the myocardial oxygen demand, which also reduces myocardial oxygen demand. Nitroglycerin is a potent vasodilator that decreases myocardial oxygen demand by decreasing the heart's workload. Nitroglycerin should not be given if certain inhibitors such as sildenafil, tadalafil, or vardenafil have been taken within the previous 12 hours as the combination of the two could cause a serious drop in blood pressure.
Treatments for angina are balloon angioplasty, in which the balloon is inserted at the end of a catheter and inflated to widen the arterial lumen. Stents to maintain the arterial widening are often used at the same time. Coronary bypass surgery involves bypassing constricted arteries with venous grafts. This is much more invasive than angioplasty.
Calcium channel blockers (such as nifedipine (Adalat) and amlodipine), isosorbide mononitrate and nicorandil are vasodilators commonly used in chronic stable angina.[ citation needed ] A new therapeutic class, called If inhibitor, has recently been made available: Ivabradine provides heart rate reduction without affecting contractility [43] leading to major anti-ischemic and antianginal efficacy. ACE inhibitors are also vasodilators with both symptomatic and prognostic benefit. Statins are the most frequently used lipid/cholesterol modifiers, which probably also stabilize existing atheromatous plaque. [44] Low-dose aspirin decreases the risk of heart attack in patients with chronic stable angina, and was part of standard treatment. However, in patients without established cardiovascular disease, the increase in hemorrhagic stroke and gastrointestinal bleeding offsets any benefits and it is no longer advised unless the risk of myocardial infarction is very high. [45]
Exercise is also a very good long-term treatment for the angina (but only particular regimens – gentle and sustained exercise rather than intense short bursts), [46] probably working by complex mechanisms such as improving blood pressure and promoting coronary artery collateralisation.
Though sometimes used by patients, evidence does not support the use of traditional Chinese herbal products (THCP) for angina. [47]
Identifying and treating risk factors for further coronary heart disease is a priority in patients with angina. This means testing for elevated cholesterol and other fats in the blood, diabetes and hypertension (high blood pressure), and encouraging smoking cessation and weight optimization.
The calcium channel blocker nifedipine prolongs cardiovascular event- and procedure-free survival in patients with coronary artery disease. New overt heart failures were reduced by 29% compared to placebo; however, the mortality rate difference between the two groups was statistically insignificant. [48]
Women with myocardial ischemia often have either no or atypical symptoms, such as palpitations, anxiety, weakness, and fatigue. Additionally, many females with angina are found to have cardiac ischemia, yet no evidence of obstructive coronary artery disease on cardiac catheterization. Evidence is accumulating that nearly half of females with myocardial ischemia have coronary microvascular disease, a condition often called microvascular angina (MVA). Small intramyocardial arterioles constrict in MVA causing ischemic pain that is less predictable than with typical epicardial coronary artery disease (CAD).
The pathophysiology is complex and still being elucidated, but there is strong evidence that endothelial dysfunction, decreased endogenous vasodilators, inflammation, changes in adipokines, and platelet activation are contributing factors. The diagnosis of MVA may require catheterization during which there is an assessment of the microcirculatory response to adenosine or acetylcholine and measurement of coronary and fractional flow reserve. New techniques include positron emission tomography (PET) scanning, cardiac magnetic resonance imaging (MRI), and transthoracic Doppler echocardiography.
Managing MVA can be challenging, for example, females with this condition have less coronary microvascular dilation in response to nitrates than do those without MVA. Females with MVA often have traditional risk factors for CAD such as obesity, dyslipidemia, diabetes, and hypertension. Aggressive interventions to reduce modifiable risk factors are an important component of management, especially smoking cessation, exercise, and diabetes management. The combination of non-nitrate vasodilators, such as calcium channel blockers and angiotensin-converting enzyme (ACE) inhibitors along with HMG-CoA reductase inhibitors (statins), also is effective in many women, and new drugs, such as Ranolazine and Ivabradine, have shown promise in the treatment of MVA. Other approaches include spinal cord stimulators, adenosine receptor blockade, and psychiatric intervention. [49] [50] [51] [52] [53] [54]
Hospital admission for people with the following symptoms is recommended, as they may have unstable angina: pain at rest (which may occur at night), pain on minimal exertion, angina that seems to progress rapidly despite increasing medical treatment. All people with suspected angina should be urgently referred to a chest pain evaluation service, for confirmation of the diagnosis and assessment of the severity of coronary heart disease. [55]
As of 2010, angina due to ischemic heart disease affects approximately 112 million people (1.6% of the global population) being slightly more common in males than females (1.7% to 1.5%). [56]
In the United States, 10.2 million are estimated to experience angina with approximately 500,000 new cases occurring each year. [11] [57] Angina is more often the presenting symptom of coronary artery disease in females than in men. The prevalence of angina rises with increasing age, with a mean age of onset of 62.3 years. [58] After five years post-onset, 4.8% of individuals with angina subsequently died from coronary heart disease. Males with angina were found to have an increased risk of subsequent acute myocardial infarction and coronary heart disease related death than women. Similar figures apply in the remainder of the Western world. All forms of coronary heart disease are much less-common in the Third World, as its risk factors are much more common in Western and Westernized countries; it could, therefore, be termed a disease of affluence.
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The condition was named "hritshoola" in ancient India and was described by Sushruta (6th century BC). [59]
The first clinical description of angina pectoris was by a British physician Dr. William Heberden in 1768. [60]
An antianginal is a drug used in the treatment of angina pectoris, a symptom of ischaemic heart disease.
Coronary artery disease (CAD), also called coronary heart disease (CHD), or ischemic heart disease (IHD), is a type of heart disease involving the reduction of blood flow to the cardiac muscle due to a build-up of atheromatous plaque in the arteries of the heart. It is the most common of the cardiovascular diseases. CAD can cause stable angina, unstable angina, myocardial ischemia, and myocardial infarction.
The coronary arteries are the arterial blood vessels of coronary circulation, which transport oxygenated blood to the heart muscle. The heart requires a continuous supply of oxygen to function and survive, much like any other tissue or organ of the body.
Chest pain is pain or discomfort in the chest, typically the front of the chest. It may be described as sharp, dull, pressure, heaviness or squeezing. Associated symptoms may include pain in the shoulder, arm, upper abdomen, or jaw, along with nausea, sweating, or shortness of breath. It can be divided into heart-related and non-heart-related pain. Pain due to insufficient blood flow to the heart is also called angina pectoris. Those with diabetes or the elderly may have less clear symptoms.
Microvascular angina (MVA), previously known as cardiac syndrome X, also known as coronary microvascular dysfunction(CMD) or microvascular coronary disease is a type of angina (chest pain) with signs associated with decreased blood flow to heart tissue but with normal coronary arteries.
A cardiac stress test is a cardiological examination that evaluates the cardiovascular system's response to external stress within a controlled clinical setting. This stress response can be induced through physical exercise or intravenous pharmacological stimulation of heart rate.
Coronary thrombosis is defined as the formation of a blood clot inside a blood vessel of the heart. This blood clot may then restrict blood flow within the heart, leading to heart tissue damage, or a myocardial infarction, also known as a heart attack.
Acute coronary syndrome (ACS) is a syndrome due to decreased blood flow in the coronary arteries such that part of the heart muscle is unable to function properly or dies. The most common symptom is centrally located pressure-like chest pain, often radiating to the left shoulder or angle of the jaw, and associated with nausea and sweating. Many people with acute coronary syndromes present with symptoms other than chest pain, particularly women, older people, and people with diabetes mellitus.
Variant angina, also known as Prinzmetal angina,vasospastic angina, angina inversa, coronary vessel spasm, or coronary artery vasospasm, is a syndrome typically consisting of angina. Variant angina differs from stable angina in that it commonly occurs in individuals who are at rest or even asleep, whereas stable angina is generally triggered by exertion or intense exercise. Variant angina is caused by vasospasm, a narrowing of the coronary arteries due to contraction of the heart's smooth muscle tissue in the vessel walls. In comparison, stable angina is caused by the permanent occlusion of these vessels by atherosclerosis, which is the buildup of fatty plaque and hardening of the arteries.
Unstable angina is a type of angina pectoris that is irregular or more easily provoked. It is classified as a type of acute coronary syndrome.
Coronary vasospasm refers to when a coronary artery suddenly undergoes either complete or sub-total temporary occlusion.
Takotsubo cardiomyopathy or takotsubo syndrome (TTS), also known as stress cardiomyopathy, is a type of non-ischemic cardiomyopathy in which there is a sudden temporary weakening of the muscular portion of the heart. It usually appears after a significant stressor, either physical or emotional; when caused by the latter, the condition is sometimes called broken heart syndrome.
A coronary stent is a tube-shaped device placed in the coronary arteries that supply blood to the heart, to keep the arteries open in patients suffering from coronary heart disease. The vast majority of stents used in modern interventional cardiology are drug-eluting stents (DES). They are used in a medical procedure called percutaneous coronary intervention (PCI). Coronary stents are divided into two broad types: drug-eluting and bare metal stents. As of 2023, drug-eluting stents were used in more than 90% of all PCI procedures. Stents reduce angina and have been shown to improve survival and decrease adverse events after a patient has suffered a heart attack—medically termed an acute myocardial infarction.
The following outline is provided as an overview of and topical guide to cardiology, the branch of medicine dealing with disorders of the human heart. The field includes medical diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease and electrophysiology. Physicians who specialize in cardiology are called cardiologists.
Coronary ischemia, myocardial ischemia, or cardiac ischemia, is a medical term for abnormally reduced blood flow in the coronary circulation through the coronary arteries. Coronary ischemia is linked to heart disease, and heart attacks. Coronary arteries deliver oxygen-rich blood to the heart muscle. Reduced blood flow to the heart associated with coronary ischemia can result in inadequate oxygen supply to the heart muscle. When oxygen supply to the heart is unable to keep up with oxygen demand from the muscle, the result is the characteristic symptoms of coronary ischemia, the most common of which is chest pain. Chest pain due to coronary ischemia commonly radiates to the arm or neck. Certain individuals such as women, diabetics, and the elderly may present with more varied symptoms. If blood flow through the coronary arteries is stopped completely, cardiac muscle cells may die, known as a myocardial infarction, or heart attack.
A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops in one of the coronary arteries of the heart, causing infarction to the heart muscle. The most common symptom is retrosternal chest pain or discomfort that classically radiates to the left shoulder, arm, or jaw. The pain may occasionally feel like heartburn. This is the dangerous type of Acute coronary syndrome.
A myocardial bridge (MB) is a common congenital heart anomaly in which one of the coronary arteries tunnels through the heart muscle (myocardium) itself.
Management of acute coronary syndrome is targeted against the effects of reduced blood flow to the affected area of the heart muscle, usually because of a blood clot in one of the coronary arteries, the vessels that supply oxygenated blood to the myocardium. This is achieved with urgent hospitalization and medical therapy, including drugs that relieve chest pain and reduce the size of the infarct, and drugs that inhibit clot formation; for a subset of patients invasive measures are also employed. Basic principles of management are the same for all types of acute coronary syndrome. However, some important aspects of treatment depend on the presence or absence of elevation of the ST segment on the electrocardiogram, which classifies cases upon presentation to either ST segment elevation myocardial infarction (STEMI) or non-ST elevation acute coronary syndrome (NST-ACS); the latter includes unstable angina and non-ST elevation myocardial infarction (NSTEMI). Treatment is generally more aggressive for STEMI patients, and reperfusion therapy is more often reserved for them. Long-term therapy is necessary for prevention of recurrent events and complications.
Kounis syndrome is defined as acute coronary syndrome caused by an allergic reaction or a strong immune reaction to a drug or other substance. It is a rare syndrome with authentic cases reported in 130 males and 45 females, as reviewed in 2017; however, the disorder is suspected of being commonly overlooked and therefore much more prevalent. Mast cell activation and release of inflammatory cytokines as well as other inflammatory agents from the reaction leads to spasm of the arteries leading to the heart muscle or a plaque breaking free and blocking one or more of those arteries.
Attilio Maseri OMRI KSG was an Italian academic and physician specialized in cardiology, considered a leading researcher in the field of ischemic heart disease. His patients included Queen Elizabeth II and Pope John Paul II.