Transcript Crisp White & Navy

Coronary Artery Disease and
Acute Coronary Syndrome
Description
• Coronary Artery Disease (CAD)
– A type of blood vessel disorder that is
included in the general category of
atherosclerosis
Description
• Atherosclerosis
– Can occur in any artery in the body
– Atheromas (fatty deposits)
• Preference for the coronary arteries
Description
• Atherosclerosis
– Terms to describe the disease process:
• Arteriosclerotic heart disease
(ASHD)
• Cardiovascular heart disease (CHD)
• Ischemic heart disease (IHD)
• CAD
Description
• Cardiovascular diseases are the major
cause of death in the US and Canada
• Heart attacks are still the leading cause
of all cardiovascular disease deaths and
deaths in general
Etiology and Pathophysiology
• Atherosclerosis is the major cause of
CAD
– Characterized by a focal deposit of
cholesterol and lipids, primarily within
the intimal wall of the artery
Etiology and Pathophysiology
• Endothelial lining altered as a result of
chemical injuries
– Hyperlipidemia
– Hypertension
Etiology and Pathophysiology
• Bacteria and/or viruses may have role in
damaging endothelium by causing local
inflammation
• C-reactive protein (CRP)
– Nonspecific marker of inflammation
– Increased in many patients with CAD
– Chronic exposure to CRP triggers the
rupture of plaques
Etiology and Pathophysiology
• Endothelial alteration 
– Platelets are activated
– Growth factor stimulates smooth
muscle proliferation
– Cell proliferation entraps lipids, which
calcify over time and form an irritant
to the endothelium on which platelets
adhere and aggregate
Etiology and Pathophysiology
• Endothelial alteration 
– Thrombin is generated
– Fibrin formation and thrombi occur
Response to Endothelial Injury
Fig. 33-3
Stages of Development in
Atherosclerosis
Fig. 33-4
Etiology and Pathophysiology
Collateral Circulation
• Analogous to “detours” around atherosclerotic
plaques
• Occur normally in coronary circulation
• But collaterals increase in the presence of
chronic ischemia
• When occlusion occurs slowly over a long
period, there is a greater chance of adequate
collateral circulation developing
Collateral Circulation
Fig. 33-5
Risk Factors for Coronary
Artery Disease
• Risk factors can be divided:
– Unmodifiable risk factors
– Modifiable risk factors
Risk Factors for Coronary
Artery Disease
• Unmodifiable risk factors:
– Age
– Gender
– Ethnicity
– Genetic predisposition
Risk Factors for Coronary
Artery Disease
• Modifiable risk factors:
– Elevated serum lipids
– Hypertension
– Smoking
– Obesity
– Physical inactivity
– Diabetes mellitus
– Stressful lifestyle
Risk Factors for Coronary
Artery Disease
• Health Promotion
– Identification of high-risk persons
– Management of high-risk persons
• Risk factor modification
–
–
–
–
Physical fitness
Health education in schools
Nutrition (weight control, ↓ fat, ↓ chol intake)
Cholesterol-lowering medications
Types of Angina
• Results when the lack of oxygen
supply is temporary and reversible
• Types of Angina
– Stable Angina
– Prinzmetal Angina
– Unstable Angina
Stable Angina Pectoris
• Chest pain occurs intermittently over a long
period with the same pattern of onset, duration,
and intensity of symptoms
• Can be controlled with medications on an
outpatient basis
• Pain usually lasts 3 to 5 minutes
– Subsides when the precipitating factor is
relieved
– Pain at rest is unusual
Silent Ischemia
Prinzmetal’s Angina
• Occurs at rest usually d/t spasm of
major coronary artery
• Spasm may occur in the absence of
CAD
Unstable Angina
• Angina that is:
– New in onset
– Occurs at rest
– Has a worsening pattern
– Unpredictable
– Considered to be an acute coronary
syndrome
– Associated with deterioration of a once stable
atherosclerotic plaque
Clinical Manifestations
Angina
• Chest pain or discomfort (d/t ischemia)
– A strange feeling, pressure, or ache in the
chest
– Constrictive, squeezing, heaving, choking, or
suffocating sensation
– Indigestion, burning
However
• Up to 80% of patients with myocardial
ischemia are asymptomatic
• Associated with diabetes mellitus and
hypertension
Location of Chest Pain
Fig. 33-12
Diagnostic Studies
Angina
•
•
•
•
•
•
•
ECG
Coronary angiography
Cardiac markers (CK MB, Troponin)
Treadmill exercise testing (stress test)
Serum lipid levels
C-reactive protein (CRP)
Nuclear imaging
Collaborative Care
Angina
• Treatment for stable angina:
–  oxygen demand and/or  oxygen
supply
– Nitrate therapy
– Stent placement
Collaborative Care
Angina
• Treatment for stable angina:
– Percutaneous coronary intervention
– Atherectomy
– Laser angioplasty
– Myocardial revascularization (CABG)
Collaborative Care
Angina
• Drug Therapy
– Antiplatelet aggregation therapy
• Aspirin: drug of choice (for MI
prevention)
• First line of treatment for angina
Collaborative Care
Angina
• Drug Therapy
– Nitrates
• 1st line therapy for treatment of
acute anginal symptoms
• Dilation of vessels
Collaborative Care
Angina
• Drug Therapy
– -Adrenergic blockers
– Calcium channel blockers
Collaborative Care
Angina
• Percutaneous coronary intervention
– Surgical intervention alternative
– Performed with local anesthesia
– Ambulatory 24 hours after the
procedure
Collaborative Care
Angina
• Stent placement
– Used to treat abrupt or threatened
abrupt closure and restenosis following
PCI
Collaborative Care
Angina
• Atherectomy
– The plaque is shaved off using a type of
rotational blade
– Decreases the incidence of abrupt
closure as compared with PCI
Collaborative Care
Angina
• Laser angioplasty
– Performed with a catheter containing
fibers that carry laser energy
– Used to precisely dissolve the blockage
Collaborative Care
Angina
• Myocardial revascularization (CABG)
– Primary surgical treatment for CAD
– Patient with CAD who has failed
medical management or has advanced
disease is considered a candidate
Clinical Manifestations
Myocardial Infarction
• Pain
– Severe, immobilizing chest pain not
relieved by rest, position change, or
nitrate administration
• The hallmark of an MI
Clinical Manifestations
• Acute Coronary Syndrome (ACS)
– Develops when the oxygen supply is
prolonged and not immediately
reversible
Clinical Manifestations
• ACS encompasses:
– Unstable angina
– Myocardial infarction (MI)
Relationships Among CAD, Stable
Angina, and MI
Fig. 33-8