Chronic stable angina overview: Difference between revisions
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==Pathophysiology== | ==Pathophysiology== | ||
Chronic stable angina results from one of three pathophysiologic processes: | |||
*Most commonly, chronic stable angina is due to '''fixed obstructive disease or [[atherosclerosis]]''' which narrows the coronary arteries. | *Most commonly, chronic stable angina is due to '''fixed obstructive disease or [[atherosclerosis]]''' which narrows the coronary arteries. | ||
:*This results in inadequate supply of blood and oxygen to meet the demands of myocardial metabolism. This supply / demand mismatch activates a molecular cascade of events that causes the release of molecules such as [[bradykinin]] and [[adenosine]] which in turn stimulate the sympathetic and [[vagal]] afferent fibers, causing the anginal pain. | :*This results in inadequate supply of blood and oxygen to meet the demands of myocardial metabolism. This supply / demand mismatch activates a molecular cascade of events that causes the release of molecules such as [[bradykinin]] and [[adenosine]] which in turn stimulate the sympathetic and [[vagal]] afferent fibers, causing the anginal pain. | ||
:*Certain conditions can increase the myocardial oxygen demand secondary to an increase in [[cardiac output]] and can exacerbate chronic stable angina. These conditions include but are not limited to [[fever]], [[thyrotoxicosis]], [[anemia]], emotional stress, and [[tachyarrythmias]]. | :*Certain conditions can increase the myocardial oxygen demand secondary to an increase in [[cardiac output]] and can exacerbate chronic stable angina. These conditions include but are not limited to [[fever]], [[thyrotoxicosis]], [[anemia]], emotional stress, and [[tachyarrythmias]]. This increase in cardiac demand is often treated with beta blockers or relief of the underlying condition. | ||
*While fixed obstructive epicardial disease is the most common cause of chronic stable angina, '''vasospasm of the epicardial artery''' can also cause angina. Angina due to spasm of an epicardial artery is known as [[Prinzmetal's angina]] or [[variant angina]]. | *While fixed obstructive epicardial disease is the most common cause of chronic stable angina, '''vasospasm of the epicardial artery''' can also cause angina. Angina due to spasm of an epicardial artery is known as [[Prinzmetal's angina]] or [[variant angina]]. [[Prinzmetal's angina]] or [[variant angina]]is often treated with [[calcium channel blockers]] to relieve the spasm. | ||
*Chronic stable angina can also result from microvascular disease as well. This is known as '''microvascular angina''' or [[Syndrome X]]. | *Chronic stable angina can also result from microvascular disease as well. This is known as '''microvascular angina''' or [[Syndrome X]]. Microvascular angina is often treated with [[calcium channel blockers]] to relieve the spasm. | ||
==Clinical presentation== | ==Clinical presentation== | ||
The majority of patients present with a history of either chest pain or chest discomfort which may be typical (occurs in the | The majority of patients present with a history of either chest pain or chest discomfort which may be '''''typical''''' (occurs in the front of the chest or anterior precordium). | ||
The presentation may also be atypical. For instance, some patients may present with [[dyspnea]] instead of chest pain and this is termed an '''angina equivalent'''. | The presentation may also be '''''atypical'''''. For instance, some patients may present with [[dyspnea]] instead of chest pain and this is termed an '''angina equivalent'''. | ||
The history should include an assessment of cardiovascular risk factors as well. | The history should include an assessment of cardiovascular risk factors as well. Physical examination may be normal or may reveal findings of [[heart failure]]. The presence of peripheral vascular disease may be associated with an increased risk of coronary artery disease [[CAD]]. | ||
==Pretest probability of Coronary Artery Disease== | |||
[[Pretest probability]] is the probability of a given disorder before the result of the diagnostic test(s) are known. In the case of angina, the initial history and physical examination can help categorize the patient into a low, intermediate or high probability group. Assessment of the pretest probability of disease aids in the selection of diagnostic studies and in the initiation of treatment. | |||
==Pretest probability | |||
Pretest probability is the probability of a given disorder before the result of the diagnostic test(s) are known. | |||
In the case of angina, the initial history and physical examination can help categorize the patient into a low, intermediate or high probability group. | |||
Assessment of the pretest probability of disease aids in the selection of diagnostic studies and in the initiation of treatment. | |||
==Diagnostic tests== | ==Diagnostic tests== | ||
===Initial Studies=== | |||
:*The goal of initial testing is to exclude the presence of an acute coronary syndrome such as [[ST elevation MI]], [[non ST elevation MI]] and [[unstable angina]]. Therefore, an [[electrocardiogram]] is performed in the patient who first presents with chronic stable angina. | :*The goal of initial testing is to exclude the presence of an acute coronary syndrome such as [[ST elevation MI]], [[non ST elevation MI]] and [[unstable angina]]. Therefore, an [[electrocardiogram]] is performed in the patient who first presents with chronic stable angina. | ||
:*The EKG may be normal in the majority of cases if ischemia is not present at the time the EKG is obtained. | :*The EKG may be normal in the majority of cases if ischemia is not present at the time the EKG is obtained. | ||
:*Other relevant findings would include evidence of [[left ventricular hypertrophy]], or Q waves in multiple leads suggestive of old [[MI]]. | :*Other relevant findings would include evidence of [[left ventricular hypertrophy]], or Q waves in multiple leads suggestive of old [[MI]]. | ||
===Exclusion of Factors That Would Exacerbate A Supply Demand Mismatch=== | |||
In the patient who first presents with unstable angina a [[hemoglobin]], [[ hematocrit]], and [[TSH]] should be obtained to exclude factors that would exacerbate a supply demand mismatch. | In the patient who first presents with unstable angina a [[hemoglobin]], [[ hematocrit]], and [[TSH]] should be obtained to exclude factors that would exacerbate a supply demand mismatch. | ||
===Studies to aid in the Management of Chronic Risk Factors=== | |||
This includes lab tests like a [[lipid profile]] and the assessment of the [[Hb a1C]] and [[glucose]]. | |||
===Imaging Studies and Studies to Assess the Magnitude of Ischemia=== | |||
*A [[chest x ray]] is often performed to assess for the presence of [[cardiomegaly]] and [[congestive heart failure]]. | *A [[chest x ray]] is often performed to assess for the presence of [[cardiomegaly]] and [[congestive heart failure]]. | ||
*Specific cardiac tests for angina include exercise [[ECG]] testing, [[myocardial perfusion imaging]], [[echocardiography]], [[stress echocardiography]] and [[coronary angiography]]<ref name="ACC">ACC/AHA 2002 guideline update for the management of patients with chronic stable angina--summary article: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (Committee on the Management of Patients With Chronic Stable Angina). | *Specific cardiac tests for angina include exercise [[ECG]] testing, [[myocardial perfusion imaging]], [[echocardiography]], [[stress echocardiography]] and [[coronary angiography]]<ref name="ACC">ACC/AHA 2002 guideline update for the management of patients with chronic stable angina--summary article: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (Committee on the Management of Patients With Chronic Stable Angina). Gibbons RJ, Abrams J, Chatterjee K, Daley J, Deedwania PC, Douglas JS, Ferguson TB Jr, Fihn SD, Fraker TD Jr, Gardin JM, O'Rourke RA, Pasternak RC, Williams SV; American College of Cardiology; American Heart Association Task Force on practice guidelines (Committee on the Management of Patients With Chronic Stable Angina). J Am Coll Cardiol. 2003 Jan 1;41(1):159-68. No abstract available. PMID: 12570960</ref>. | ||
Gibbons RJ, Abrams J, Chatterjee K, Daley J, Deedwania PC, Douglas JS, Ferguson TB Jr, Fihn SD, Fraker TD Jr, Gardin JM, O'Rourke RA, Pasternak RC, Williams SV; American College of Cardiology; American Heart Association Task Force on practice guidelines (Committee on the Management of Patients With Chronic Stable Angina). | |||
J Am Coll Cardiol. 2003 Jan 1;41(1):159-68. No abstract available. | |||
===Diagnostic Criteria=== | |||
To confirm or qualify for the diagnosis of chronic stable angina, at least one of the following additional criteria for coronary artery disease and / or ischemia must be present: | |||
:*New and/or dynamic ST-depression >0.05 mV, ST-elevation >0.1 mV, or symmetric T wave inversion >0.2 mV on a resting ECG | :*New and/or dynamic ST-depression >0.05 mV, ST-elevation >0.1 mV, or symmetric T wave inversion >0.2 mV on a resting ECG | ||
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==Treatment== | ==Treatment== | ||
*Treatment for chronic stable angina includes: | *Treatment for chronic stable angina includes: | ||
:* | :*Lifestyle modification, | ||
:* | :*Pharmacotherapy and | ||
:* | :*Revascularization procedures([[PCI]], [[CABG]]). | ||
*It is also important to identify any exacerbating factors like [[anemia]], [[thyrotoxicosis]], valvular heart disease or decompensated [[heart failure]] and treat them | *It is also important to identify any exacerbating factors like [[anemia]], [[thyrotoxicosis]], valvular heart disease or decompensated [[heart failure]] and treat them. | ||
*Smoking cessation counselling, diet and weight management, promoting physical exercise, | *Smoking cessation counselling, diet and weight management, promoting physical exercise, blood pressure and [[diabetes]] control are all part of risk factor modification and should be stressed at each clinic visit. | ||
*Specific medical therapy includes antiplatelets(like [[ASA]], [[clopidogrel]]), antianginals(like [[nitrates]], [[beta blockers]], [[calcium channel blockers]], | *Specific medical therapy includes antiplatelets (like [[ASA]], [[clopidogrel]]), antianginals (like [[nitrates]], [[beta blockers]], [[calcium channel blockers]], lipid-lowering agents, [[ACE]] inhibitors and [[angiotensin receptor blocking agents]]. | ||
*Coronary revascularization is recommended when optimal medical therapy has failed to reduce symptoms or severe atherosclerotic disease or high risk criteria on noninvasive testing <ref>2007 chronic angina focused update of the ACC/AHA 2002 guidelines for the management of patients with chronic stable angina: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines Writing Group to develop the focused update of the 2002 guidelines for the management of patients with chronic stable angina. | *Coronary revascularization is recommended when optimal medical therapy has failed to reduce symptoms or severe atherosclerotic disease or high risk criteria on noninvasive testing <ref>2007 chronic angina focused update of the ACC/AHA 2002 guidelines for the management of patients with chronic stable angina: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines Writing Group to develop the focused update of the 2002 guidelines for the management of patients with chronic stable angina. | ||
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J Am Coll Cardiol. 2007 Dec 4;50(23):2264-74. No abstract available. Erratum in: J Am Coll Cardiol. 2007 Dec 4;50(23):e1. Pasternak, Richard C [removed]. | J Am Coll Cardiol. 2007 Dec 4;50(23):2264-74. No abstract available. Erratum in: J Am Coll Cardiol. 2007 Dec 4;50(23):e1. Pasternak, Richard C [removed]. | ||
PMID: 18061078</ref>. | PMID: 18061078</ref>. | ||
:*Options available for revascularization | :*Options available for revascularization include percutaneous coronary intervention[[PCI]] and coronary artery bypass grafting[[CABG]]. | ||
:*In patients with chronic stable angina, the factors influencing the choice of coronary revascularization therapy (percutaneous coronary intervention or coronary artery bypass surgery) are varied and complex. The severity of symptoms, lifestyle, extent of objective ischemia, and underlying risks must be weighed against the benefits of revascularization and the patient’s preference, as well as local availability and expertise. | :*In patients with chronic stable angina, the factors influencing the choice of coronary revascularization therapy (percutaneous coronary intervention or coronary artery bypass surgery) are varied and complex. The severity of symptoms, lifestyle, extent of objective ischemia, and underlying risks must be weighed against the benefits of revascularization and the patient’s preference, as well as local availability and expertise. | ||
:*Evidence from randomized trials and large revascularization registers can guide these decisions, but the past decade has seen | :*Evidence from randomized trials and large revascularization registers can guide these decisions, but the past decade has seen significant improvements in medical treatment, bypass surgery and percutaneous coronary intervention. | ||
==Prognosis of Chronic Stable Angina== | ==Prognosis of Chronic Stable Angina== | ||
Ischemic heart disease remains number one cause of mortality in developed countries. | Ischemic heart disease remains number one cause of mortality in developed countries. The prognosis of stable angina varies widely depending on severity of symptoms, extent of atherosclerosis and presence of other risk factors and co-morbidities. The presence of impaired left ventricular function is associated with a poor prognosis. | ||
The prognosis of stable angina varies widely depending on severity of symptoms, extent of atherosclerosis and presence of other risk factors and co-morbidities. | |||
==References== | ==References== | ||
Revision as of 01:30, 18 July 2011
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Chronic stable angina Microchapters | ||
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Classification | ||
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Differentiating Chronic Stable Angina from Acute Coronary Syndromes | ||
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Diagnosis | ||
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Alternative Therapies for Refractory Angina | ||
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Discharge Care | ||
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Guidelines for Asymptomatic Patients | ||
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Case Studies | ||
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Chronic stable angina overview On the Web | ||
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Risk calculators and risk factors for Chronic stable angina overview | ||
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editors-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]
Overview
- Angina pectoris, commonly known as angina is chest pain [1] due to ischemia (a lack of blood and hence oxygen supply) of the heart muscle, generally due to obstruction or spasm of the coronary arteries (the heart's blood vessels).
- Coronary artery disease or atherosclerosis of the coronary arteries is the most common cause of angina. The term derives from the Greek ankhon ("strangling") and the Latin pectus ("chest"), and can therefore be translated as "a strangling feeling in the chest".
- In angina pectoris the sensation of chest discomfort can be a feeling of tightness, heaviness, or pain.
Pathophysiology
Chronic stable angina results from one of three pathophysiologic processes:
- Most commonly, chronic stable angina is due to fixed obstructive disease or atherosclerosis which narrows the coronary arteries.
- This results in inadequate supply of blood and oxygen to meet the demands of myocardial metabolism. This supply / demand mismatch activates a molecular cascade of events that causes the release of molecules such as bradykinin and adenosine which in turn stimulate the sympathetic and vagal afferent fibers, causing the anginal pain.
- Certain conditions can increase the myocardial oxygen demand secondary to an increase in cardiac output and can exacerbate chronic stable angina. These conditions include but are not limited to fever, thyrotoxicosis, anemia, emotional stress, and tachyarrythmias. This increase in cardiac demand is often treated with beta blockers or relief of the underlying condition.
- While fixed obstructive epicardial disease is the most common cause of chronic stable angina, vasospasm of the epicardial artery can also cause angina. Angina due to spasm of an epicardial artery is known as Prinzmetal's angina or variant angina. Prinzmetal's angina or variant anginais often treated with calcium channel blockers to relieve the spasm.
- Chronic stable angina can also result from microvascular disease as well. This is known as microvascular angina or Syndrome X. Microvascular angina is often treated with calcium channel blockers to relieve the spasm.
Clinical presentation
The majority of patients present with a history of either chest pain or chest discomfort which may be typical (occurs in the front of the chest or anterior precordium).
The presentation may also be atypical. For instance, some patients may present with dyspnea instead of chest pain and this is termed an angina equivalent.
The history should include an assessment of cardiovascular risk factors as well. Physical examination may be normal or may reveal findings of heart failure. The presence of peripheral vascular disease may be associated with an increased risk of coronary artery disease CAD.
Pretest probability of Coronary Artery Disease
Pretest probability is the probability of a given disorder before the result of the diagnostic test(s) are known. In the case of angina, the initial history and physical examination can help categorize the patient into a low, intermediate or high probability group. Assessment of the pretest probability of disease aids in the selection of diagnostic studies and in the initiation of treatment.
Diagnostic tests
Initial Studies
- The goal of initial testing is to exclude the presence of an acute coronary syndrome such as ST elevation MI, non ST elevation MI and unstable angina. Therefore, an electrocardiogram is performed in the patient who first presents with chronic stable angina.
- The EKG may be normal in the majority of cases if ischemia is not present at the time the EKG is obtained.
- Other relevant findings would include evidence of left ventricular hypertrophy, or Q waves in multiple leads suggestive of old MI.
Exclusion of Factors That Would Exacerbate A Supply Demand Mismatch
In the patient who first presents with unstable angina a hemoglobin, hematocrit, and TSH should be obtained to exclude factors that would exacerbate a supply demand mismatch.
Studies to aid in the Management of Chronic Risk Factors
This includes lab tests like a lipid profile and the assessment of the Hb a1C and glucose.
Imaging Studies and Studies to Assess the Magnitude of Ischemia
- A chest x ray is often performed to assess for the presence of cardiomegaly and congestive heart failure.
- Specific cardiac tests for angina include exercise ECG testing, myocardial perfusion imaging, echocardiography, stress echocardiography and coronary angiography[2].
Diagnostic Criteria
To confirm or qualify for the diagnosis of chronic stable angina, at least one of the following additional criteria for coronary artery disease and / or ischemia must be present:
- New and/or dynamic ST-depression >0.05 mV, ST-elevation >0.1 mV, or symmetric T wave inversion >0.2 mV on a resting ECG
- Definite evidence of ischemia on stress echocardiography, myocardial scintigraphy (e.g. an area of clear reversible ischemia), or ECG-only stress test (e.g., significant dynamic ST shift, horizontal or downsloping)
- Angiographic evidence of epicardial coronary artery stenosis of >70% diameter reduction and/or evidence for intraluminal arterial thrombus.
Treatment
- Treatment for chronic stable angina includes:
- It is also important to identify any exacerbating factors like anemia, thyrotoxicosis, valvular heart disease or decompensated heart failure and treat them.
- Smoking cessation counselling, diet and weight management, promoting physical exercise, blood pressure and diabetes control are all part of risk factor modification and should be stressed at each clinic visit.
- Specific medical therapy includes antiplatelets (like ASA, clopidogrel), antianginals (like nitrates, beta blockers, calcium channel blockers, lipid-lowering agents, ACE inhibitors and angiotensin receptor blocking agents.
- Coronary revascularization is recommended when optimal medical therapy has failed to reduce symptoms or severe atherosclerotic disease or high risk criteria on noninvasive testing [3].
- Options available for revascularization include percutaneous coronary interventionPCI and coronary artery bypass graftingCABG.
- In patients with chronic stable angina, the factors influencing the choice of coronary revascularization therapy (percutaneous coronary intervention or coronary artery bypass surgery) are varied and complex. The severity of symptoms, lifestyle, extent of objective ischemia, and underlying risks must be weighed against the benefits of revascularization and the patient’s preference, as well as local availability and expertise.
- Evidence from randomized trials and large revascularization registers can guide these decisions, but the past decade has seen significant improvements in medical treatment, bypass surgery and percutaneous coronary intervention.
Prognosis of Chronic Stable Angina
Ischemic heart disease remains number one cause of mortality in developed countries. The prognosis of stable angina varies widely depending on severity of symptoms, extent of atherosclerosis and presence of other risk factors and co-morbidities. The presence of impaired left ventricular function is associated with a poor prognosis.
References
- ↑ "MerckMedicus : Dorland's Medical Dictionary". Retrieved 2009-01-09.
- ↑ ACC/AHA 2002 guideline update for the management of patients with chronic stable angina--summary article: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (Committee on the Management of Patients With Chronic Stable Angina). Gibbons RJ, Abrams J, Chatterjee K, Daley J, Deedwania PC, Douglas JS, Ferguson TB Jr, Fihn SD, Fraker TD Jr, Gardin JM, O'Rourke RA, Pasternak RC, Williams SV; American College of Cardiology; American Heart Association Task Force on practice guidelines (Committee on the Management of Patients With Chronic Stable Angina). J Am Coll Cardiol. 2003 Jan 1;41(1):159-68. No abstract available. PMID: 12570960
- ↑ 2007 chronic angina focused update of the ACC/AHA 2002 guidelines for the management of patients with chronic stable angina: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines Writing Group to develop the focused update of the 2002 guidelines for the management of patients with chronic stable angina. Fraker TD Jr, Fihn SD; 2002 Chronic Stable Angina Writing Committee; American College of Cardiology; American Heart Association, Gibbons RJ, Abrams J, Chatterjee K, Daley J, Deedwania PC, Douglas JS, Ferguson TB Jr, Gardin JM, O'Rourke RA, Williams SV, Smith SC Jr, Jacobs AK, Adams CD, Anderson JL, Buller CE, Creager MA, Ettinger SM, Halperin JL, Hunt SA, Krumholz HM, Kushner FG, Lytle BW, Nishimura R, Page RL, Riegel B, Tarkington LG, Yancy CW. J Am Coll Cardiol. 2007 Dec 4;50(23):2264-74. No abstract available. Erratum in: J Am Coll Cardiol. 2007 Dec 4;50(23):e1. Pasternak, Richard C [removed]. PMID: 18061078