View source for Angina pectoris

{{dablink|This article is about chest pain due to oxygen shortage in the heart. For ''angina tonsillaris'' see [[tonsillitis]]. For the infection of the soft tissues in the floor of the mouth, see [[Ludwig's angina]]. }}
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 | DiseasesDB     = 8695
 | ICD10          = {{ICD10|I|20||i|20}}
 | ICD9           = {{ICD9|413}} 
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 | OMIM           = 
 | MedlinePlus    = 
 | eMedicineSubj  = med
 | eMedicineTopic = 133
 | MeshID         = D000787
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==Overview==

'''Angina pectoris''', commonly known as '''angina''', is [[chest pain]] due to [[ischemia]] (a lack of blood and hence [[oxygen]] supply) of the [[myocardium|heart muscle]], generally due to obstruction or spasm of the [[coronary circulation|coronary arteries]] (the heart's blood vessels). [[Coronary heart disease|Coronary artery disease]], the main cause of angina, is due to [[atherosclerosis]] of the cardiac arteries. The term derives from the [[Greek language|Greek]] ''ankhon'' ("strangling") and the [[Latin]] ''pectus'' ("chest"), and can therefore be translated as "a strangling feeling in the chest". 

It is common to equate severity of angina with risk of fatal cardiac events. There is a weak relationship between severity of pain and degree of oxygen deprivation in the heart muscle (i.e. there can be severe pain with little or no risk of a heart attack, and a heart attack can occur without pain)

Worsening ("crescendo") 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 herald [[myocardial infarction]] (a heart attack), they require urgent medical attention and are generally treated as a presumed heart attack.

Angina pectoris is the sensation of chest discomfort which can be a feeling of tightness, heaviness, or pain. It is secondary to a condition in which the heart muscle is not supplied with sufficient oxygen and this causes [[chest pain]].

Angina pectoris is a sign of [[coronary heart disease]]. If it occurs chronically this is called [[stable angina]]. If it occurs at rest or in an accelerating pattern this is called an [[acute coronary syndrome]] and can be a symptom of either:
#[[Unstable angina]]: An open artery with insufficient blood flow to the heart but without irreversible damage
#[[Non ST elevation MI]]: An open artery with insufficient blood flow to the heart with irreversible damage
#[[ST elevation MI]]: A closed artery with insufficient blood flow to the heart and irreversible damage

==Epidemiology==

Roughly 6.3 million Americans are estimated to experience angina. Angina is more often the presenting symptom of coronary artery disease in women than in men. The prevalence of angina rises with an increase in age. 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 [[Diseases of affluence|disease of affluence]]. The increase of [[tobacco smoking|smoking]], [[obesity]] and other risk factors has already led to an increase in angina and related diseases in countries such as China.

==Pathophysiology==
Increase in heart rate results in increased oxygen demand by the heart. The heart has a limited ability to increase its oxygen intake during episodes of increased demand. Therefore, an increase in oxygen demand by the heart (eg, during exercise) has to be met by a proportional increase in blood flow to the heart. 

[[Myocardial ischemia]] can result from:
# a reduction of blood flow to the heart caused by the [[stenosis]] or spasm of the heart's arteries
# resistance of the blood vessels
# reduced oxygen-carrying capacity of the blood.

[[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 reduced oxygen-carrying capacity of [[blood]], as seen with severe [[anemia]] (low number of red blood cells), or long-term [[tobacco smoking|smoking]].

==Symptoms==

Most 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, jaw, or shoulders. Typical locations for [[radiation (medicine)|radiation]] of 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.  It usually lasts for about 1 to 5 minutes, and is relieved by rest or specific anti-angina medication. Chest pain lasting only a few seconds is normally not angina. 

[[Myocardial ischemia]] comes about when the myocardia (the heart muscles) receive insufficient blood and oxygen to function normally either because of increased oxygen demand by the myocardia or by decreased supply to the myocardia. This inadequate [[perfusion]] of blood and the resulting reduced delivery of oxygen and nutrients, is 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 [[tobacco smoking|cigarette smoking]], [[Diabetes mellitus|diabetes]], [[Hypercholesterolemia|high cholesterol]], [[hypertension|high blood pressure]], sedentary lifestyle and [[family history (medicine)|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 thought to be caused by spasms of the artery. It occurs more in younger women.

Angina may further be classified as stable or unstable angina. Stable angina refers to the more common understanding of angina related to myocardial ischemia. Typical presentations 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. Symptoms typically abate several minutes following cessation of precipitating activities and resume when activity resumes. In this way, stable angina may be thought of as being similar to claudication symptoms. 

Unstable angina on the other hand strays from the activity correlation seen in stable angina. It may occur unpredictably at rest which may be a serious indicator of an impending heart attack. What differentiates stable angina from unstable angina (other than symptoms) is the pathophysiology of the atherosclerosis. In stable angina, the developing [[atheroma]] is protected with a fibrous cap. This cap may rupture in unstable angina, allowing blood clots to precipitate and further decrease the lumen of the coronary vessel. This explains why angina appears to be independent to activity.

==Diagnosis==

In angina patients who are 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 [[Electrocardiogram#ST_segment|ST segment]] may be observed. To elicit these changes, an [[Cardiac stress test|exercise ECG test]] ("treadmill test") may be performed, during which the patient exercises to their maximum ability before fatigue, breathless or, importantly, pain supervenes; if characteristic ECG changes are documented (typically more than 1 mm of flat or downsloping ST depression), the test is considered diagnostic for angina. The exercise test is also useful in looking for other markers of myocardial ischaemia: blood pressure response (or lack thereof, particularly a drop in systolic pressure), dysrhythmia and chronotropic response. Other alternatives to a standard exercise test include a [[Cardiac stress test|thallium scintigram]] (in patients that cannot exercise enough for the purposes of 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 catheterization|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 surgery|coronary artery bypass graft]] (CABG), treatment only with medication, or other treatments. In patients who are in hospital 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.

==Treatment==

The main goals of treatment in angina pectoris are relief of symptoms, slowing progression of the disease, and reduction of future events, especially [[myocardial infarction|heart attacks]] and of course death. An [[aspirin]] (75 mg to 100 mg) per day has been shown to be beneficial for all patients with stable angina that have no problems with its use. [[Beta blockers]] (eg. propranolol,atenolol etc.) are some few examples, have a large body of evidence in morbidity and mortality benefits (fewer symptoms and disability and live longer) and short-acting [[nitroglycerin]] medications are used for symptomatic relief of angina. [[Calcium channel blocker]]s (such as [[nifedipine]] (Adalat®) and [[amlodipine]]), [[Isosorbide mononitrate]] and [[nicorandil]] are vasodilators commonly used in chronic stable angina. A new therapeutic class, called If inhibitor, has recently been made available: [[ivabradine]] provides pure heart rate reduction,.<ref>Sulfi S, Timmis AD. Ivabradine - the first selective sinus node I(f) channel inhibitor in the treatment of stable angina. ''Int J Clin Pract'' 2006;60:222-8. PMID 16451297. [http://www.pubmedcentral.gov/articlerender.fcgi?pubmedid=16451297 ''Full text'']</ref> leading to major anti-ischemic and antianginal efficacy.  [[ACE inhibitor|ACE inhibitors]] are also vasodilators with both symptomatic and prognostic benefit and lastly, [[statins]] are the most frequently used lipid/cholesterol modifiers which probably also stabilise existing atheromatous plaque. 

Surprising perhaps is that exercise is also a very good long term treatment for angina<ref> {{cite journal|title=Exercise conditioning in older coronary patients. Submaximal lactate response and endurance capacity|journal=circulation|date=1993 - 08|first=Ades|last=PA|coauthors= ML Waldmann, ET Poehlman, P Gray, ED Horton, ES Horton and MM LeWinter |volume=88|issue=|pages=572-577|id= |url=http://circ.ahajournals.org/cgi/content/abstract/circulationaha;88/2/572|format=|accessdate=2007-02-08}}</ref> (but only particular regimes - gentle and sustained exercise rather than dangerous intense short bursts), probably working by complex mechanisms such improving blood pressure and promoting coronary artery collateralisation. 

Identifying and treating risk factors for further coronary heart disease is a priority in patients with angina. This means testing for [[hypercholesterolemia|elevated cholesterol]] and other fats in the blood, [[diabetes mellitus|diabetes]] and [[hypertension]] (high blood pressure), encouraging [[smoking cessation|stopping smoking]] and [[weight loss|weight optimisation]].

Even though known victims may wear a necklace or bracelet identifying the medical condition, EMS (ambulance) is still required.

[[Ranolazine]] (Ranexa) is a new class of anti anginal drug that was approved by the Food and Drug Administration (FDA)

Recently, University of Cincinnati medical researchers in cardiology have tried to use a non-invasive, non-surgical collecting tool to gather harvested erythropoietic bone marrow-based adult stem cells and coax them into regrowing new coronary blood vessels to supply the cardiac muscle's cells (cardiac myocytes) with oxygenated blood, with some success- leading to larger Phase 2 trials.

The largest randomised trial of an anti-anginal drug to date is the ACTION trial. It included 7,665 patients with stable angina pectoris. ACTION demonstrated that the calcium channel blocker nifedipine (Adalat®) prolongs cardiovascular event- and procedure-free survival in patients with coronary artery disease. For example new overt heart failures were reduced by 29% compared to placebo. This finding confirms the vascular-protective effects of nifedipine. <ref>[http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=15351192&ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum Poole-Wilson P, et al. Effect of long-acting nifedipine on mortality and cardiovascular morbidity in patients with stable angina requiring treatment (ACTION trial): randomised controlled trial. Lancet 2004;364:849–57.]</ref>

==References==
{{Reflist|2}}

==Major studies==
*[http://www.adalat.com/professionals-home/research/action-trial/ Information on ACTION - A Coronary Disease Trial Investigating Outcome with Nifedipine GITS in Patients with chronic stable angina pectoris]

==Additional Resources==
* [http://www.themdtv.org The MD TV: Comments on Hot Topics, State of the Art Presentations in Cardiovascular Medicine, Expert Reviews on Cardiovascular Research]
* [http://www.clinicaltrialresults.org Clinical Trial Results: An up to dated resource of Cardiovascular Research]

==External links==
*[http://www.bhf.org.uk/hearthealth/index.asp?secondlevel=77&thirdlevel=353&artID=434 British Heart Foundation - Angina]
*[http://anginapectorisonline.com Angina Pectoris Online] Resource for nurses and those in similar professions.
*[http://www.hipsknees.info/flash31/ypo.swf Angina Pectoris Animation Video 3D]
*[http://www.adalat.com Official Adalat® (Nifedipine) site, Bayer]


{{Circulatory system pathology}}
{{SIB}}
[[Category:Ischemic heart diseases]]
[[Category:Cardiology]]
[[Category:Emergency medicine]]

[[ar:ذبحة صدرية]]
[[da:Angina pectoris]]
[[de:Angina Pectoris]]
[[el:Στηθάγχη]]
[[es:Angina de pecho]]
[[eo:Angino]]
[[fr:Angine de poitrine]]
[[it:Angina pectoris]]
[[he:תעוקת לב]]
[[ku:Angîna pektorîs]]
[[nl:Angina pectoris]]
[[ja:狭心症]]
[[no:Angina pectoris]]
[[pl:Choroba niedokrwienna serca]]
[[pt:Angina]]
[[qu:Sunqup'iti nanay]]
[[ru:Стенокардия]]
[[fi:Angina pectoris]]
[[sv:Kärlkramp]]
[[tr:Angina pektoris]]
[[zh:心绞痛]]

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