Chest Pain / Angina Pectoris: Difference between revisions

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In 1772 doctor William Heberden first described angina pectoris, he wrote: ''“They who are afflicted with it are seized, while they are walking (more especially if it be up hill), with a painful and most disagreeable sensation in the breast, which seems as if it would extinguish life if it were to increase or to continue, but the moment the patient stands still all this uneasiness vanishes”''.<cite>Davies</cite>
[[File:Heart_coronary_artery.jpg|thumb|400px|An epicardial coronary artery with a atherosclerotic narrowing]]
Stable angina (pectoris) is a clinical syndrome characterized by discomfort in the chest, jaw, shoulder, back, or arms, typically elicited by exertion or emotional stress and relieved
by rest or nitroglycerin. It can be attributed to myocardial ischemia which is most commonly caused by atherosclerotic coronary artery disease or aortic valve stenosis.  


Three major coronary arteries provide the heart with oxygenated blood, the right coronary artery (RCA), the left coronary artery (LCA) and the circumflex artery (Cx). When the coronary arteries are affected by atherosclerosis and the lumen of the coronary arteries narrows, the heart receives less oxygenated blood and becomes hypoxic, which results in angina pectoris.  
Three major coronary arteries supply the heart with oxygenated blood, the right coronary artery (RCA), the left anterior descending coronary artery (LAD) and the left circumflex artery (LCx). When the coronary arteries are affected by atherosclerosis and the lumen of the coronary arteries progressively narrow, a dysbalance between myocardial oxygen supply and myocardial oxygen consumption may occur, causing myocardial ischemia.
In stable angina this imbalance mainly occurs when oxygen demand increases due to exercise, increased heart rate, contractility or wall stress.


Complete history and physical examination are essential to determine angina pectoris as diagnosis and to exclude other causes of chest pain, such as aorta dissection, arrhythmias, pulmonary embolism, pneumonia, heartburn, hyperventilation or musculoskeletal problems.<cite>Sampson</cite>
A complete history and physical examination are essential to support the diagnosis (stable) angina pectoris and to exclude other (acute) causes of chest pain such as an acute coronary syndrome, aortic dissection, arrhythmias, pulmonary embolism, (tension) pneumothorax or pneumonia, gastroesophageal reflux or spams, hyperventilation or musculoskeletal pain. <Cite>REFNAME2</Cite> In addition, laboratory tests and specific cardiac investigations are often necessary.


===History===
==History==
Patients often experience angina pectoris as if a elephant stands on their chest. Because the heart itself has very few nerves the pain can be sensible elsewhere in the upper body, mainly arms, jaw and/or back.<cite>Foreman</cite> Some patients only complain about stomach ache so the presentation can be very a specific.<cite>Canto</cite>,<cite>Pope</cite>
[[File:Chest_pain_areas.svg|thumb|Typical chest pain is retrosternal. Pain may radiate to the arms, jaw, and / or back.]]
Patients often describe angina pectoris as pressure, tightness, or heaviness located centrally in the chest, and sometimes as strangling, constricting, or burning. The pain often radiates elsewhere in the upper body, mainly arms, jaw and/or back. <Cite>REFNAME3</Cite> Some patients only complain about abdominal pain so the presentation can be aspecific. <Cite>REFNAME4</Cite>, <Cite>REFNAME5</Cite>


Angina pectoris however has some characteristics that can help to differentiate between other causes of (chest) pain. Angina pectoris is gradual in onset and offset, with the intensity increasing and decreasing over several minutes. The pain is constant and does not change with respiration or position. If patients had angina pectoris before they will recognize the pain immediately.<cite>Constant</cite>
Angina pectoris however has some characteristics that can help to differentiate between other causes of (chest) pain. Angina pectoris is usually is brief and gradual in onset and offset, with the intensity increasing and decreasing over several minutes. The pain does not change with respiration or position. If patients had angina pectoris previously they are often able to recognize the pain immediately.  <Cite>REFNAME6</Cite>
Angina pectoris is a manifestation of arterial insufficiency and usually occurs with increasing oxygen demand such as during exercise. As soon as the demand is decreased (by stopping the exercise for example) complaints usually disappears within a few minutes.
Another way to relieve pain is by administration of nitro-glycerine. Nitro-glycerine spray is a vasodilator which reduces venous return to the heart and therefore decreases the workload and therefore oxygen demand. It also dilates the coronary arteries and increases coronary blood flow. <Cite>REFNAME7</Cite> The response to nitro-glycerine is however not specific for angina pectoris, a similar response may be seen with oesophageal spasm or other gastrointestinal problems because nitro-glycerine relaxes smooth muscle tissue. <Cite>REFNAME8</Cite>


Angina pectoris usually occurs during exercise when the demand for oxygenated blood increases. Coronary arteries with a narrowed lumen can not meet the demand of oxygenated blood during exercise. As soon as the exercise is aborted angina pectoris decreases. This is called stable angina pectoris.
Depending on the characteristics, chest pain can be identified as typical angina, atypical angina or non-cardiac chest pain, see Table 1.


Unstable angina pectoris means angina pectoris at rest which consists less than two months. Over time the angina pectoris develops to more often, severe and prolonged, so that symptoms are to occur at less and less effort than before.<cite>Anderson</cite>
{| class="wikitable" border="1" width="600px"
|-
Stable angina pectoris responds to nitro-glycerine spray, unstable angina pectoris does not.
! align="center" colspan="2" | Table 1. Clinical classification of chest pain <Cite>REFNAME17</Cite>
Nitro-glycerine spray is a venodilator which reduces venous return to the heart and therefore decreases the workload and therefore oxygen demand. It also vasodilates the coronary arteries and increases coronary blood flow.<cite>Abrams</cite>
|-
|valign="top" align="left"|Typical angina (definite)
|Meets three of the following characteristics:
*Substernal chest discomfort of characteristic quality and duration
*Provoked by exertion or emotional stress
*Relieved by rest and/or nitroglycerine
|-
| valign="top"|Atypical angina (probable)
|Meets two of these characteristics
|-
| valign="top"|Non-cardiac chest pain
|Meets one or none of the characteristics
|}


Nitro-glycerine is however not specific for angina pectoris, a similar response may be seen with oesophageal spasm or other gastrointestinal problems because nitro-glycerine also relaxes smooth muscle.<cite>Henrikson</cite>
The classification of chest pain in combination with age and sex is helpful in estimating the pretest likelihood of angiographically significant coronary artery disease, see Table 2.  


During angina pectoris so called vegetative symptoms can occur, this includes sweating, nausea, paleface, anxiety and agitation. The idea is that the vegetative nerve system is more active in a reaction to stress.<cite>Antman</cite>
{| class="wikitable" border="1" width="600px"
|-
! align="left" colspan = "7" | Table 2. Clinical pre-test probabilities <sup>a</sup> in patients with stable chest pain symptoms. <Cite>REFNAME20</Cite>
|-
| align="center"|
| align="center" colspan="2" bgcolor="#FFFFFF" | <b>Typical angina</b>
| align="center" colspan="2" bgcolor="#FFFFFF" | <b>Atypical angina</b>
| align="center" colspan="2" bgcolor="#FFFFFF" | <b>Non-anginal pain</b>
|-
! Age
! Men
! Women
! Men
! Women
! Men
! Women
|-
! 30-39
| align="center" bgcolor="#F0F8FF" | 59
| align="center" bgcolor="#F0F8FF" | 28
| align="center" bgcolor="#F0F8FF" | 29
| align="center" bgcolor="#FFFFFF" | 10
| align="center" bgcolor="#F0F8FF" | 18
| align="center" bgcolor="#FFFFFF" | 5
|-
! 40-49
| align="center" bgcolor="#FFCCCC" | 69
| align="center" bgcolor="#F0F8FF" | 37
| align="center" bgcolor="#F0F8FF" | 38
| align="center" bgcolor="#FFFFFF" | 14
| align="center" bgcolor="#F0F8FF" | 25
| align="center" bgcolor="#FFFFFF" | 8
|-
! 50-59
| align="center" bgcolor="#FFCCCC" | 77
| align="center" bgcolor="#F0F8FF" | 47
| align="center" bgcolor="#F0F8FF" | 49
| align="center" bgcolor="#F0F8FF" | 20
| align="center" bgcolor="#F0F8FF" | 34
| align="center" bgcolor="#FFFFFF" | 12
|-
! 60-69
| align="center" bgcolor="#FFCCCC" | 84
| align="center" bgcolor="#F0F8FF" | 58
| align="center" bgcolor="#F0F8FF" | 59
| align="center" bgcolor="#F0F8FF" | 28
| align="center" bgcolor="#F0F8FF" | 44
| align="center" bgcolor="#F0F8FF" | 17
|-
! 70-79
| align="center" bgcolor="#FF69B4" | 89
| align="center" bgcolor="#FFCCCC" | 68
| align="center" bgcolor="#FFCCCC" | 69
| align="center" bgcolor="#F0F8FF" | 37
| align="center" bgcolor="#F0F8FF" | 54
| align="center" bgcolor="#F0F8FF" | 24
|-
! >80
| align="center" bgcolor="#FF69B4" | 93
| align="center" bgcolor="#FFCCCC" | 76
| align="center" bgcolor="#FFCCCC" | 78
| align="center" bgcolor="#F0F8FF" | 47
| align="center" bgcolor="#F0F8FF" | 65
| align="center" bgcolor="#F0F8FF" | 32
|-
| colspan = "7" bgcolor="#FFFFFF"|
|-
! colspan = "7" | ECG = electrocardiogram; PTP = pre-test probability; SCAD = stable coronary artery disease.
|-
| colspan = "7" bgcolor="#FFFFFF" | <b><sup>a</sup></b> Probabilities of obstructive coronary disease shown reflect the estimates for patients aged 35, 45, 55, 65, 75 and 85 years.
*Groups in <i>white boxes</i> have a PTP <15% and hence can be managed without further testing.
*Groups in <i>blue boxes</i> have a PTP of 15–65%. They could have an exercise ECG if feasible as the initial test. However, if local expertise and availability permit a non-invasive imaging based test for ischaemia this would be preferable given the superior diagnostic capabilities of such tests. In young patients radiation issues should be considered.
*Groups in <i>light pink boxes</i> have PTPs between 66–85% and hence should have a non-invasive imaging functional test for making a diagnosis of SCAD.
*In groups in <i>dark pink boxes</i> the PTP is >85% and one can assume that SCAD is present. They need risk stratification only.
|}


===Physical Examination===
The severity of complaints can be classified according to the Canadian Cardiovascular Society as shown in Table 3
Oxygen deficiency of the heart leads to ischemia, ischemia and the discomfort the patient experiences lead to sympathetic activation of the nervous system. This is detectable during physical examination by an increase in heart rate and elevation in blood pressure.
Ischemia can also cause a temporarily impairment in myocardial function, on auscultation you could hear a paradoxically split second heart sound, a third or fourth heart sound and a mitral regurgitation murmur. All these findings however disappear with resolution of the ischemia. Up to date: Pathophysiology and clinical presentation of ischemic chest pain, geen bronvermelding.


===ECG===
{| class="wikitable" border="1" width="600px"
[[File:TBC00003.jpg|200px|thumb|right|]]
|-
! colspan="2" | Table 3. Classification of angina severity according to the Canadian Cardiovascular Society
|-
! width="100"| ''Class''
| ''Level of Symptoms''
|-
! valign="top"| Class I
| 'Ordinary activity does not cause angina'
Angina with strenuous or rapid or prolonged exertion only
|-
! valign="top"| Class II
| 'Slight limitation of ordinary activity'
Angina on walking or climbing stairs rapidly, walking uphill or exertion after meals, in cold weather, when under emotional stress, or only during the first few hours after awakening
|-
! valign="top"| Class III
| 'Marked limitation of ordinary physical activity'
Angina on walking one or two blocks on the level or one flight of stairs at a normal pace under normal conditions
|-
! valign="top"| Class IV
| 'Inability to carry out physical activity without discomfort' or 'angina at rest'
|}


The electrocardiogram (ECG) is an easy and important tool to differentiate between myocardial ischemia and infarction. Patients with unstable angina pectoris will show abnormalities on the ECG at rest, in particular ST depression.
During angina pectoris ‘vegetative’ symptoms can occur, including sweating, nausea, paleface, anxiety and agitation. This is probably caused by the autonomic nerve system in reaction to stress. <Cite>REFNAME9</Cite>
Patients with stable angina pectoris are likely to have a completely normal ECG at rest, exercise ECG testing will be necessary to show any abnormalities.<cite>Ref1</cite> During exercise ECG testing an ECG is made during cycling on a home trainer or walking on a treadmill. While exercising the oxygen demand of the heart increases, if the narrowed coronary arteries are unable to supply enough oxygenated blood, the patient develops pain on the chest and the ECG will show abnormalities.<cite>Fox</cite>


===Additional Research===
Finally, it is important to differentiate unstable angina (indicating an acute coronary syndrome or even myocardial infarction requiring urgent treatment) from stable angina. Unstable angina typically is severe, occurs without typical provocation and does not disappear with rest, and has a longer duration than stable angina. It is important to initiate prompt treatment in these patients, as described in the acute coronary syndromes chapter.
If the ECG made during exercise testing does not show any abnormalities angina pectoris becomes very unlikely. If the ECG does show abnormalities during exercise testing additional research needs to be done.<cite>Fox2</cite> Depending on the hospital one of the below standing research will be done.
# Exercise echocardiography means that an echocardiography is made directly after exercise. The poorly perfused parts of the heart will show less activity.<cite>Amanullah</cite>
# Myocardium Perfusion Scintigraphy (MPS) is able to show the perfusion of the heart during exercise and at rest.<cite>Brown</cite>
# MRI can be done with vasodilatory dobutamine or stimulating adenosine to assess how the heart behaves during exercise.<cite>Kwong</cite>
The findings on stress testing can be used to determine the choice between medical therapy and revascularization in patients with stable angina. Coronary angiography is recommended based upon symptoms, left ventricular function, and estimated risk by stress testing.<cite>Fraker</cite>


'''Table 1'''
==Physical Examination==
 
==Coronary Angiography==
There are no specific signs in angina pectoris. Physical examination of a patient with (suspected) angina pectoris is important to assess the presence of hypertension,
In patients with unstable angina pectoris early coronary angiography possibly followed by revascularization is usually performed within 4 to 24 hours of admission in the hospital. In most clinical trials this strategy has shown a reduction in the incidence of death or nonfatal myocardial infraction.<cite>Anderson2</cite>
valvular heart disease (in particular aortic valve stenosis) or hypertrophic obstructive cardiomyopathy. It should include the body-mass index, evidence of non-coronary vascular disease which may be asymptomatic and other signs of co-morbid conditions. E.g.: absence of palpable pulsations in the dorsal foot artery is associated with an 8 fold increase in the likelihood of coronary artery disease.


A CAG is an X ray examination of the coronary arteries, a catheter is inserted into the femoral artery or into the radial artery. The tip of the catheter is positioned at the beginning of the coronary arteries and contrast fluid is injected. Contrast is visible by X ray and the images that are obtained are called angiograms.
==Electrocardiogram (ECG)==
The electrocardiogram (ECG) is an important tool to differentiate between unstable angina (acute coronary syndrome) and stable angina in addition to the patient’s history. Patients with unstable angina pectoris are likely to show abnormalities on the ECG at rest, in particular ST-segment deviations.
Although a resting ECG may show signs of coronary artery disease such as pathological Q-waves indicating a previous MI or other abnormalities, many patients with stable angina pectoris have a normal ECG at rest. Therefore exercise ECG testing may be necessary to show signs of myocardial ischemia. <Cite>REFNAME10</Cite>


On an angiogram stenoses will be visible, if the stenosis is significant coronary intervention will take place. Ideally this happens immediately following the CAG but not all hospitals that are entitled to carry out CAG are qualified to perform percutaneous coronary intervention (PCI).  
'''Exercise ECG testing''' is performed with gradually increasing intensity on a treadmill or a bicycle ergo-meter. Exercise increases the oxygen demand of the heart, potentially revealing myocardial ischemia by the occurrence of ST-segment depression on the ECG. <Cite>REFNAME11</Cite>


==Treatment==
==Laboratory Testing==
===Medication===
Laboratory testing in the setting of angina pectoris can be useful to differentiate between different causes of the pain, including an acute coronary syndrome in which there will be elevation of the marker of myocardial necrosis. Anaemia should be ruled out as a cause of ischemia. Renal function is important for pharmacological therapy. Moreover, it might assist in establishing a cardiovascular risk profile.
In patients with stable angina pectoris percutaneous coronary intervention does not offer any benefit in terms of death, myocardial infarction, or the need for subsequent revascularization compared with conservative medical treatment.<cite>Katritsis</cite>


Initial treatment of stable angina pectoris therefore focuses on medication to keep the workload of the heart as low as possible. β blockers lower heart rate and blood pressure, this decreases the oxygen demand of the heart.<cite>Garcia</cite> Nitrates dilatate the coronary arteries so the heart receives more oxygenated blood.<cite>Abrams2</cite> Anticoagulants (aspirin) to reduce the risk of development of a thrombus in the coronary arteries.<cite>Hennekens</cite>
==Stress Testing in Combination with Imaging==
Some patients are unable to perform physical exercise. Furthermore, in patients with resting ECG abnormalities the exercise ECG is associated with low sensitivity and specificity.  


Apart from starting medication the patient needs to minimize any present risk factors like smoking, overweight and drinking alcohol. ''See chronic coronary diseases''.
{| class="wikitable" border="1" width="600px"
 
|-
==Percutaneous Coronary Intervention==
|colspan = "7" | <b>Table 4. Characteristics of tests commonly used to diagnose the presence of coronary artery disease. <Cite>REFNAME20</Cite></b>
The procedure of PCI is similar to a CAG, except this time a catheter with an inflatable balloon will be brought at the site of the stenosis. Inflation of the balloon within the coronary artery will crush the atherosclerosis and eliminate the stenosis. To prevent that the effect of the balloon is only temporarily a stent is often positioned at the site of the stenosis.
 
==Coronary Artery Bypass Graft==
There are circumstances in which CABG should be performed.
 
{| class="wikitable" border="1" style="width: 700px"
|-  
|-  
! style="background: #34abff; color: white" | Class of recommendations
| bgcolor="#FFFFFF" rowspan="2"|
! style="background: #34abff; color: white" | Definition
|align="center" colspan="2" bgcolor="#FFFFFF" | <b>Diagnosis of CAD</b>
|-
| align="center" bgcolor="#FFFFFF" | <b>Sensitivity (%)</b>
| align="center" bgcolor="#FFFFFF" | <b>Specificity (%)</b>
|-
| <b>Exercise ECG <sup>a, 91, 94, 95</sup></b>
!45–50
!85–90
|-
| <b>Exercise stress echocardiography <sup>96</sup></b>
!80–85
!80–88
|-
|-
| style="background: #74fb3f" | '''Class I'''
| <b>Exercise stress SPECT <sup>96-99</sup></b>
| style="background: white" | Evidence and/or general agreement that a given treatment or procedure is beneficial, useful, effective.
!73–92
!63–87
|-
|-
| style="background: #fdaa02" | '''Class II'''
| <b>Dobutamine stress echocardiography <sup>96</sup></b>
| style="background: white" | Conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of the given treatment or procedure.
!79–83
* Weight of evidence/opinion is in favour of usefulness/efficacy.
!82–86
* Usefulness/efficacy is less well established by evidence/opinion.
|-
|-
| style="background: #fd3535" | '''Class III'''
| <b>Dobutamine stress MRI <sup>b,100</sup></b>
| style="background: white" | Evidence or general agreement that the given treatment or procedure is not usefull effective, and in some cases may be harmful.
!79–88
!81–91
|-
|-
| colspan="2" | Class I - There is evidence and/or general agreement that CABG should be performed in patients with STEMI in the following settings.
| <b>Vasodilator stress echocardiography <sup>96</sup></b>
|}
!72–79
!92–95
|-
| <b>Vasodilator stress SPECT <sup>96, 99</sup></b>
!90–91
!75–84
|-
| <b>Vasodilator stress MRI <sup>b,98, 100-102</sup></b>
!67–94
!61–85
|-
| <b>Coronary CTA <sup>c,103-105</sup></b>
!95–99
!64–83
|-
| <b>Vasodilator stress PET <sup>97, 99, 106</sup></b>
!81–97
!74–91
|-
| colspan="3" bgcolor="#FFFFFF"| <b>CAD</b> = coronary artery disease; <b>CTA</b> = computed tomography angiography; <b>ECG</b> = electrocardiogram; <b>MRI</b> = magnetic resonance imaging; <b>PET</b> = positron emission tomography; <b>SPECT</b> = single photon emission computed tomography.
|-
| colspan="3"|<b><sup>a</sup></b> Results without/with minimal referral bias.


CABG does not eliminate the stenosis like PCI does. Using the internal thoracic arteries or the saphenous veins from the legs a bypass is made around the stenosis. The bypass originates from the aorta and terminates directly after the stenosis. Thereby restoring the blood supply to the ramifications.
<b><sup>b</sup></b> Results obtained in populations with medium-to-high prevalence of disease without compensation for referral bias.


=Myocardial Infarction=
<b><sup>c</sup></b> Results obtained in populations with low-to-medium prevalence of disease.
|}


In 2006 425.425 people died from a heart attack, 1.255.000 new and recurrent coronary attacks took place, about 34% died, 17.600.000 victims of angina, heart attack and other forms of coronary heart disease are still living.
[[File:Algorithm_for_the_initial_evaluation_of_patients_with_clinical_symptoms_of_angina.svg|thumb|right|500px|Figure 1. Algorithm for the initial evaluation of patients with clinical symptoms of angina]]


These numbers only account for the United States.  
If the ECG made during exercise testing does not show any abnormalities myocardial ischemia becomes unlikely as cause of the complaints. If the diagnosis is still in doubt, the following additional tests may be performed.
#Exercise echocardiography means that an echocardiography is made before and during different stages up to peak exercise in order to identify wall motion abnormalities. <Cite>REFNAME12</Cite> An alternative is pharmacological stress testing using dobutamine.
#Myocardium Perfusion Scintigraphy (MPS) is able to show the perfusion of the heart during exercise and at rest based on radiopharmaceutical tracer uptake . <Cite>REFNAME13</Cite>
#Magnetic Resonance Imaging can be done with vasodilatory adenosine or stimulating dobutamine to detect wall motion abnormalities induced by ischemia during pharmacological stress. <Cite>REFNAME14</Cite>


==Pathofysiology==
The findings on stress testing can be used to determine the choice between medical therapy only or medical therapy and invasive assessment of the coronary anatomy in patients with stable angina. Coronary angiography is recommended based upon the severity of symptoms, likelihood of ischemic disease, and risk of the patient for subsequent complications including mortality based on risk scores. <Cite>REFNAME15</Cite> For the algorithm for the initial evaluation of patients with clinical symptoms of angina see Figure 1.
A heart attack or myocardial infarction (MI) is an acute presentation of a process that has been going on much longer. The process responsible is atherosclerosis. Atherosclerosis is a chronic disease of the arteries in which artery walls thicken by deposition of fatty materials such as cholesterol. The result over decades are plaques, which can narrow the lumen of the arteries significantly and progressively causing symptoms as angina pectoris. Plaques can also suddenly rupture, trigger a cascade which results in a thrombus and thereby cause myocardial infarction.<cite>Davies3</cite>


==History==
==Coronoary Angiography==
Classic presentation of a myocardial infarction is acute chest pain which lasts longer than a few minutes. PMID 16304077 The pain does not decrease at rest and is only temporarily relieved with nitroglycerin. Common accompanying symptoms are radiating pain to shoulder, arm, back and/or jaw. PMID 10099685 Shortness of breath can occur, as well as sweating, fainting, nausea and vomiting, so called vegetative symptoms. Some patients not really complain about chest pain but more about abdominal pain so as with angina pectoris the presentation can be very a specific. PMID 10866870, PMID 10751787
Coronary angiography (CAG) can assist in the diagnosis and the selection of treatment options for stable angina pectoris. During CAG, the coronary anatomy is visualized including the presence of coronary luminal stenoses.  A catheter is inserted into the femoral artery or into the radial artery. The tip of the catheter is positioned at the beginning of the coronary arteries and contrast fluid is injected. The contrast is made visible by X ray and the images that are obtained are called angiograms.
If stenoses are visible, the operator will judge whether this stenosis is significant and eligible for percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG).  


It is important to complete the history with information about past history (prior history of ischemic events or vascular disease), risk factors for cardiovascular disease (o.a. smoking, hypertension, hyperlipidemia, obesity) and family history (direct family with myocardial infarction and/or sudden cardiac death).  
==Treatment==
Stable angina pectoris is always treated with medical therapy aimed at reducing risk and at alleviating symptoms. Current guidelines recommend revascularization in patients with persistent symptoms despite optimal medical therapy. <Cite>REFNAME16</Cite> Furthermore, revascularization is indicated in case of large areas of myocardial ischemia (such as a left main stem stenosis, a proximal LAD stenosis or significant three vessel disease) and in the presence of high-risk features such as ventricular arrhythmia, heart failure, widening of QRS during ischemia, axis deviation during ischemia or hypotension during ischemia. The choice between PCI and CABG depends on the coronary anatomy and clinical characteristics and the choice should be made in a team including (interventional) cardiologists and thoracic surgeons.  


Signs of heart failure such as orthopnea (not able to sleep without a pillow), progressive dyspnoea and oedematous ankles are indicative for the extent of the problem. PMID 15289388
==Medical Therapy==
Initial treatment of stable angina pectoris focuses on medication reducing the oxygen demand of the heart. ß blockers lower heart rate and blood pressure. <Cite>REFNAME17</Cite> Nitrates dilatate the coronary arteries and reduce venous return if used to abort an episode of pain. <Cite>REFNAME18</Cite> Antiplatelet therapy (aspirin) reduces the risk of development of a thrombus and thus acute (coronary) ischemic events. <Cite>REFNAME19</Cite>
Risk factors like smoking, overweight, hypertension, dyslipidemia and diabetes need to be treated in order to prevent disease progression and future events. See chronic coronary diseases.  


A suspected myocardial infarction should be rapidly evaluated to initiate appropriate therapy.  
==PCI==
The procedure of PCI is similar to a CAG, except this time a catheter with an inflatable balloon will be brought to the site of the stenosis. Inflation of the balloon within the coronary artery will crush the atherosclerosis and eliminate the stenosis. To prevent collapse of the arteric wall and restenosis, a stent is often positioned at the site of the stenosis.  


==Physical Examination==
==CABG==
On physical examination evidence of systemic hypoperfusion can be found such as hypotension, tachycardia, impaired cognition, pale and ashen skin. PMID 15289388
With CABG, a bypass is placed around the stenosis using the internal thoracic arteries or the saphenous veins from the legs. The bypass originates proximal from the stenosis and terminates distally from the stenosis. The operation usually requires the use of cardiopulmonary bypass and cardiac arrest, however in certain cases the grafts can be placed on the beating heart (“off-pump” surgery)
 
If during auscultation pulmonary crackles are heard and pitting oedema of the ankles is seen heart failure is complicating the myocardial infarction.
== References ==
 
History and physical examination are helpful to determine myocardial infarction as diagnosis and to exclude other causes of chest pain, such as angina pectoris, aorta dissection, arrhythmias, pulmonary embolism, pneumonia, heartburn, hyperventilation or musculoskeletal problems. PMID 15289388
 
 
==References==
<biblio>
<biblio>
#Davies pmid=11756201
#REFNAME1 pmid=11756201
#Sampson pmid=4997794
#REFNAME2 pmid=4997794
#Foreman pmid=10099685
#REFNAME3 pmid=10099685
#Canto pmid=10866870
#REFNAME4 pmid=10866870
#Pope pmid=10751787
#REFNAME5 pmid=10751787
#Constant pmid=6831781
#REFNAME6 pmid=6831781
#Anderson pmid=17692738
#REFNAME7 pmid=3925741
#Anderson2 pmid=17692738
#REFNAME8 pmid=14678917
#Abrams pmid=3925741
#REFNAME9 pmid=15289388
#Abrams2 pmid=3925741
#REFNAME10 pmid=8375424
#Henrikson pmid=14678917
#REFNAME11 pmid=17162834
#Antman pmid=15289388
#REFNAME12 pmid=1352191
#Fox pmid=17162834
#REFNAME13 pmid=2007701
#Fox2 pmid=17162834
#REFNAME14 pmid=12566362
#Amanullah pmid=1352191
#REFNAME15 pmid=18061078
#Brown pmid=2007701
#REFNAME16 pmid=20802248
#Kwong pmid=12566362
#REFNAME17 pmid=16735367
#Fraker pmid=18061078
#REFNAME18 pmid=3925741
#Katritsis pmid=15927966
#REFNAME19 pmid=9355934
#Garcia pmid=16735367
#REFNAME20 pmid=23996286
#Hennekens pmid=9355934
#Davies3 pmid=11084798
 
#Ref1 pmid=8375424
</biblio>
</biblio>

Latest revision as of 12:50, 16 September 2013

An epicardial coronary artery with a atherosclerotic narrowing

Stable angina (pectoris) is a clinical syndrome characterized by discomfort in the chest, jaw, shoulder, back, or arms, typically elicited by exertion or emotional stress and relieved by rest or nitroglycerin. It can be attributed to myocardial ischemia which is most commonly caused by atherosclerotic coronary artery disease or aortic valve stenosis.

Three major coronary arteries supply the heart with oxygenated blood, the right coronary artery (RCA), the left anterior descending coronary artery (LAD) and the left circumflex artery (LCx). When the coronary arteries are affected by atherosclerosis and the lumen of the coronary arteries progressively narrow, a dysbalance between myocardial oxygen supply and myocardial oxygen consumption may occur, causing myocardial ischemia. In stable angina this imbalance mainly occurs when oxygen demand increases due to exercise, increased heart rate, contractility or wall stress.

A complete history and physical examination are essential to support the diagnosis (stable) angina pectoris and to exclude other (acute) causes of chest pain such as an acute coronary syndrome, aortic dissection, arrhythmias, pulmonary embolism, (tension) pneumothorax or pneumonia, gastroesophageal reflux or spams, hyperventilation or musculoskeletal pain. [1] In addition, laboratory tests and specific cardiac investigations are often necessary.

History

Typical chest pain is retrosternal. Pain may radiate to the arms, jaw, and / or back.

Patients often describe angina pectoris as pressure, tightness, or heaviness located centrally in the chest, and sometimes as strangling, constricting, or burning. The pain often radiates elsewhere in the upper body, mainly arms, jaw and/or back. [2] Some patients only complain about abdominal pain so the presentation can be aspecific. [3], [4]

Angina pectoris however has some characteristics that can help to differentiate between other causes of (chest) pain. Angina pectoris is usually is brief and gradual in onset and offset, with the intensity increasing and decreasing over several minutes. The pain does not change with respiration or position. If patients had angina pectoris previously they are often able to recognize the pain immediately. [5] Angina pectoris is a manifestation of arterial insufficiency and usually occurs with increasing oxygen demand such as during exercise. As soon as the demand is decreased (by stopping the exercise for example) complaints usually disappears within a few minutes. Another way to relieve pain is by administration of nitro-glycerine. Nitro-glycerine spray is a vasodilator which reduces venous return to the heart and therefore decreases the workload and therefore oxygen demand. It also dilates the coronary arteries and increases coronary blood flow. [6] The response to nitro-glycerine is however not specific for angina pectoris, a similar response may be seen with oesophageal spasm or other gastrointestinal problems because nitro-glycerine relaxes smooth muscle tissue. [7]

Depending on the characteristics, chest pain can be identified as typical angina, atypical angina or non-cardiac chest pain, see Table 1.

Table 1. Clinical classification of chest pain [8]
Typical angina (definite) Meets three of the following characteristics:
  • Substernal chest discomfort of characteristic quality and duration
  • Provoked by exertion or emotional stress
  • Relieved by rest and/or nitroglycerine
Atypical angina (probable) Meets two of these characteristics
Non-cardiac chest pain Meets one or none of the characteristics

The classification of chest pain in combination with age and sex is helpful in estimating the pretest likelihood of angiographically significant coronary artery disease, see Table 2.

Table 2. Clinical pre-test probabilities a in patients with stable chest pain symptoms. [9]
Typical angina Atypical angina Non-anginal pain
Age Men Women Men Women Men Women
30-39 59 28 29 10 18 5
40-49 69 37 38 14 25 8
50-59 77 47 49 20 34 12
60-69 84 58 59 28 44 17
70-79 89 68 69 37 54 24
>80 93 76 78 47 65 32
ECG = electrocardiogram; PTP = pre-test probability; SCAD = stable coronary artery disease.
a Probabilities of obstructive coronary disease shown reflect the estimates for patients aged 35, 45, 55, 65, 75 and 85 years.
  • Groups in white boxes have a PTP <15% and hence can be managed without further testing.
  • Groups in blue boxes have a PTP of 15–65%. They could have an exercise ECG if feasible as the initial test. However, if local expertise and availability permit a non-invasive imaging based test for ischaemia this would be preferable given the superior diagnostic capabilities of such tests. In young patients radiation issues should be considered.
  • Groups in light pink boxes have PTPs between 66–85% and hence should have a non-invasive imaging functional test for making a diagnosis of SCAD.
  • In groups in dark pink boxes the PTP is >85% and one can assume that SCAD is present. They need risk stratification only.

The severity of complaints can be classified according to the Canadian Cardiovascular Society as shown in Table 3

Table 3. Classification of angina severity according to the Canadian Cardiovascular Society
Class Level of Symptoms
Class I 'Ordinary activity does not cause angina'

Angina with strenuous or rapid or prolonged exertion only

Class II 'Slight limitation of ordinary activity'

Angina on walking or climbing stairs rapidly, walking uphill or exertion after meals, in cold weather, when under emotional stress, or only during the first few hours after awakening

Class III 'Marked limitation of ordinary physical activity'

Angina on walking one or two blocks on the level or one flight of stairs at a normal pace under normal conditions

Class IV 'Inability to carry out physical activity without discomfort' or 'angina at rest'

During angina pectoris ‘vegetative’ symptoms can occur, including sweating, nausea, paleface, anxiety and agitation. This is probably caused by the autonomic nerve system in reaction to stress. [10]

Finally, it is important to differentiate unstable angina (indicating an acute coronary syndrome or even myocardial infarction requiring urgent treatment) from stable angina. Unstable angina typically is severe, occurs without typical provocation and does not disappear with rest, and has a longer duration than stable angina. It is important to initiate prompt treatment in these patients, as described in the acute coronary syndromes chapter.

Physical Examination

There are no specific signs in angina pectoris. Physical examination of a patient with (suspected) angina pectoris is important to assess the presence of hypertension, valvular heart disease (in particular aortic valve stenosis) or hypertrophic obstructive cardiomyopathy. It should include the body-mass index, evidence of non-coronary vascular disease which may be asymptomatic and other signs of co-morbid conditions. E.g.: absence of palpable pulsations in the dorsal foot artery is associated with an 8 fold increase in the likelihood of coronary artery disease.

Electrocardiogram (ECG)

The electrocardiogram (ECG) is an important tool to differentiate between unstable angina (acute coronary syndrome) and stable angina in addition to the patient’s history. Patients with unstable angina pectoris are likely to show abnormalities on the ECG at rest, in particular ST-segment deviations. Although a resting ECG may show signs of coronary artery disease such as pathological Q-waves indicating a previous MI or other abnormalities, many patients with stable angina pectoris have a normal ECG at rest. Therefore exercise ECG testing may be necessary to show signs of myocardial ischemia. [11]

Exercise ECG testing is performed with gradually increasing intensity on a treadmill or a bicycle ergo-meter. Exercise increases the oxygen demand of the heart, potentially revealing myocardial ischemia by the occurrence of ST-segment depression on the ECG. [12]

Laboratory Testing

Laboratory testing in the setting of angina pectoris can be useful to differentiate between different causes of the pain, including an acute coronary syndrome in which there will be elevation of the marker of myocardial necrosis. Anaemia should be ruled out as a cause of ischemia. Renal function is important for pharmacological therapy. Moreover, it might assist in establishing a cardiovascular risk profile.

Stress Testing in Combination with Imaging

Some patients are unable to perform physical exercise. Furthermore, in patients with resting ECG abnormalities the exercise ECG is associated with low sensitivity and specificity.

Table 4. Characteristics of tests commonly used to diagnose the presence of coronary artery disease. [9]
Diagnosis of CAD
Sensitivity (%) Specificity (%)
Exercise ECG a, 91, 94, 95 45–50 85–90
Exercise stress echocardiography 96 80–85 80–88
Exercise stress SPECT 96-99 73–92 63–87
Dobutamine stress echocardiography 96 79–83 82–86
Dobutamine stress MRI b,100 79–88 81–91
Vasodilator stress echocardiography 96 72–79 92–95
Vasodilator stress SPECT 96, 99 90–91 75–84
Vasodilator stress MRI b,98, 100-102 67–94 61–85
Coronary CTA c,103-105 95–99 64–83
Vasodilator stress PET 97, 99, 106 81–97 74–91
CAD = coronary artery disease; CTA = computed tomography angiography; ECG = electrocardiogram; MRI = magnetic resonance imaging; PET = positron emission tomography; SPECT = single photon emission computed tomography.
a Results without/with minimal referral bias.

b Results obtained in populations with medium-to-high prevalence of disease without compensation for referral bias.

c Results obtained in populations with low-to-medium prevalence of disease.

Figure 1. Algorithm for the initial evaluation of patients with clinical symptoms of angina

If the ECG made during exercise testing does not show any abnormalities myocardial ischemia becomes unlikely as cause of the complaints. If the diagnosis is still in doubt, the following additional tests may be performed.

  1. Exercise echocardiography means that an echocardiography is made before and during different stages up to peak exercise in order to identify wall motion abnormalities. [13] An alternative is pharmacological stress testing using dobutamine.
  2. Myocardium Perfusion Scintigraphy (MPS) is able to show the perfusion of the heart during exercise and at rest based on radiopharmaceutical tracer uptake . [14]
  3. Magnetic Resonance Imaging can be done with vasodilatory adenosine or stimulating dobutamine to detect wall motion abnormalities induced by ischemia during pharmacological stress. [15]

The findings on stress testing can be used to determine the choice between medical therapy only or medical therapy and invasive assessment of the coronary anatomy in patients with stable angina. Coronary angiography is recommended based upon the severity of symptoms, likelihood of ischemic disease, and risk of the patient for subsequent complications including mortality based on risk scores. [16] For the algorithm for the initial evaluation of patients with clinical symptoms of angina see Figure 1.

Coronoary Angiography

Coronary angiography (CAG) can assist in the diagnosis and the selection of treatment options for stable angina pectoris. During CAG, the coronary anatomy is visualized including the presence of coronary luminal stenoses. A catheter is inserted into the femoral artery or into the radial artery. The tip of the catheter is positioned at the beginning of the coronary arteries and contrast fluid is injected. The contrast is made visible by X ray and the images that are obtained are called angiograms. If stenoses are visible, the operator will judge whether this stenosis is significant and eligible for percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG).

Treatment

Stable angina pectoris is always treated with medical therapy aimed at reducing risk and at alleviating symptoms. Current guidelines recommend revascularization in patients with persistent symptoms despite optimal medical therapy. [17] Furthermore, revascularization is indicated in case of large areas of myocardial ischemia (such as a left main stem stenosis, a proximal LAD stenosis or significant three vessel disease) and in the presence of high-risk features such as ventricular arrhythmia, heart failure, widening of QRS during ischemia, axis deviation during ischemia or hypotension during ischemia. The choice between PCI and CABG depends on the coronary anatomy and clinical characteristics and the choice should be made in a team including (interventional) cardiologists and thoracic surgeons.

Medical Therapy

Initial treatment of stable angina pectoris focuses on medication reducing the oxygen demand of the heart. ß blockers lower heart rate and blood pressure. [8] Nitrates dilatate the coronary arteries and reduce venous return if used to abort an episode of pain. [18] Antiplatelet therapy (aspirin) reduces the risk of development of a thrombus and thus acute (coronary) ischemic events. [19] Risk factors like smoking, overweight, hypertension, dyslipidemia and diabetes need to be treated in order to prevent disease progression and future events. See chronic coronary diseases.

PCI

The procedure of PCI is similar to a CAG, except this time a catheter with an inflatable balloon will be brought to the site of the stenosis. Inflation of the balloon within the coronary artery will crush the atherosclerosis and eliminate the stenosis. To prevent collapse of the arteric wall and restenosis, a stent is often positioned at the site of the stenosis.

CABG

With CABG, a bypass is placed around the stenosis using the internal thoracic arteries or the saphenous veins from the legs. The bypass originates proximal from the stenosis and terminates distally from the stenosis. The operation usually requires the use of cardiopulmonary bypass and cardiac arrest, however in certain cases the grafts can be placed on the beating heart (“off-pump” surgery)

References

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