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ANGINA PECTORIS
Brunner 2012
Chapter 28
ANGINA PECTORIS
• Angina pectoris is a clinical syndrome usually
characterized by episodes or paroxysms of
pain or pressure in the anterior chest.
• The cause is usually insufficient coronary
blood flow.
• In other words, the need for oxygen exceeds
the supply.
Pathophysiology
• Angina is usually caused by atherosclerotic disease.
• Several factors are associated with typical anginal pain:
• 1-Physical exertion, which can precipitate an attack by
increasing myocardial oxygen demand
• 2-Exposure to cold, which can cause vasoconstriction and
an elevated blood pressure, with increased oxygen
demand.
• 3-Eating a heavy meal, which increases the blood flow to
the mesenteric area for digestion, thereby reducing the
blood supply available to the heart .
• 4-Stress or any emotion-causing the release of adrenaline
and increasing blood pressure, which may accelerate the
heart rate and increase the myocardial workload.
Types of Angina
• Stable angina:predictable and consistent pain that
occurs on exertion and is relieved by rest
• Unstable angina (also called preinfarction angina or
crescendo=increase angina): symptoms occur more
frequently and last longer than stable angina. The
threshold for pain is lower, and pain may occur at
rest.
• Intractable or refractory angina:severe
incapacitating chest pain.
…Types of Angina
• Variant angina (also called Prinzmetal’s
angina): pain at rest with eversible STsegment elevation; thought to be caused by
coronary artery vasospasm.
• Silent ischemia: objective evidence of
ischemia (such as electrocardiographic
changes with a stress test), but patient reports
no symptoms.
Clinical Manifestations
• Ischemia of the heart muscle may
produce pain or other symptoms, varying
in severity.
• The pain is often (retrosternal area).
• Typically, the pain or discomfort is poorly
localized and may radiate to the neck,
jaw, shoulders, and inner aspects of the
upper arms, usually the left arm.
• The patient often feels tightness or a heavy, choking,
or strangling sensation that has a viselike‫فشاری‬,
insistent quality.
• The patient with diabetes mellitus may not have
severe pain with angina because the neuropathy .
• A feeling of weakness or numbness in the arms,
wrists, and hands may accompany the pain, as may
shortness of breath,pallor, diaphoresis, dizziness or
lightheadedness, and nausea and vomiting.
• When these symptoms appear alone,they are
called angina-like symptoms.
• Anxiety may accompany angina.
• An important characteristic of angina is that it
abates or subsides with rest or nitroglycerin.
Gerontologic Considerations
• The elderly person with angina may not exhibit the
typical pain profile because of the diminished
responses of neurotransmitters that occur in the aging
process.
• Often, the presenting symptom in the elderly is
dyspnea.
• If they do have pain, it is atypical pain that radiates to
both arms rather than just the left arm.
• Sometimes,there are no symptoms (“silent” CAD),
making recognition and diagnosis a clinical challenge
Assessment and Diagnostic Findings
• ECG
• CAD is believed to result from inflammation of
the arterial endothelium.
• C-reactive protein (CRP) is a marker for
inflammation of vascular endothelium.
• High blood levels of CRP have been associated
with increased coronary artery calcification and
risk of an acute cardiovascular event (eg, MI) in
seemingly healthy individuals .
• An elevated blood level of homocysteine, an
amino acid, has also been proposed as an
independent risk factor for cardiovascular
disease.
• However, studies have not supported the
relationship between mild to moderate
elevations of homocysteine and atherosclerosis .
• No study has yet shown that reducing
homocysteine levels reduces the risk of CAD.
Medical Management
• The objectives of the medical management of
angina are to decrease the oxygen demand of the
myocardium and to increase the oxygen supply.
• percutaneous coronary interventional
(PCI)procedures (eg, percutaneous transluminal
coronary angioplasty [PTCA], intracoronary
stents, and
• atherectomy),
• CABG,
PHARMACOLOGIC THERAPY
• Among medications used to control
angina are nitroglycerin,betaadrenergic blocking agents, calcium
channel blockers, and antiplatelet
agents.
Nitroglycerin
.
• Nitroglycerin dilates primarily the veins and, in
higher doses, also dilates the arteries.
• Dilation of the veins causes venous pooling of blood
throughout the body.
• As a result, less blood returns to the heart, and filling
pressure (preload) is reduced.
• Nitrates in higher doses also relax the systemic
arteriolar bed and lower blood pressure (decreased
afterload).
• Nitroglycerin may be given by several
routes: sublingual tablet or spray, topical
agent, and intravenous administration.
• IV nitroglycerin usually is not given if the
systolic blood pressure is 90 mm Hg or
less.
4
Beta-Adrenergic Blocking Agents
• Beta-blockers such as propranolol
(Inderal), metoprolol (Lopressor, Toprol),
and atenolol (Tenormin) appear to
reduce myocardial oxygen consumption
by blocking the beta-adrenergic
sympathetic stimulation to the heart.
• reduced myocardial contractility.
• The dose can be titrated to achieve a
resting heart rate of 50 to 60 beats
per minute.
• Patients taking beta-blockers are
cautioned not to stop taking them
abruptly, because angina may
worsen and MI may develop.
Calcium Channel Blocking Agents
• increase myocardial oxygen supply by dilating the
smooth muscle wall of the coronary arterioles;
they decrease myocardial oxygen demand by
reducing systemic arterial pressure and the
workload of the left ventricle.
• amlodipine (Norvasc), verapamil (Calan, Isoptin,
Verelan), and diltiazem (Cardizem, Dilacor,
Tiazac).
• Amlodipine (Norvasc) and felodipine (Plendil)
are the calcium channel blockers of choice for
patients with heart failure.
Antiplatelet and Anticoagulant
Medications
• Antiplatelet medications are administered to
prevent platelet aggregation, which impedes
blood flow.
Aspirin
• Aspirin prevents platelet activation and
reduces the incidence of MI and death in
patients with CAD.
• A 160- to 325-mg dose of aspirin should be
given to the patient with angina as soon as the
diagnosis is made (eg, in the emergency room
or physician’s office) and then continued with
81 to 325 mg daily.
Clopidogrel and Ticlopidine.
• Clopidogrel (Plavix) or ticlopidine (Ticlid)
is given to patients who are allergic to
aspirin or given in addition to aspirin in
patients at high risk for MI.
• Unlike aspirin,these medications take a
few days to achieve their antiplatelet
effect.
Heparin
• Heparin therapy is usually considered therapeutic
when the aPTT is 1.5 to 2 times the normal aPTT value.
• A subcutaneous injection of low-molecular-weight
heparin(LMWH; enoxaparin [Lovenox] or dalteparin
[Fragmin]) may be used.
• the patient is monitored for signs and symptoms of
external and internal bleeding.
• Avoiding intramuscular injections.
• A decrease in platelet count or skin lesions at heparin
injection sites may indicate heparin-induced
thrombocytopenia (HIT).
Oxygen Administration
• Oxygen therapy is usually initiated at the
onset of chest pain in an attempt to increase
the amount of oxygen delivered to the
myocardium and to decrease pain.