Topic 4 Flashcards
Normal Structure Heart
Heart ◦ Mediastinal space ◦ Covered by pericardium Composed of three layers ◦ Epicardium ◦ Myocardium ◦ Endocardium
Coronary Artery Disease (CAD)
Progressive narrowing of coronary arteries by atherosclerosis
◦ Coronary heart disease
◦ Atherosclerotic heart disease
Pathophysiology of CAD
Injury to epithelial cells in intima
◦ Platelet aggregation
◦ Migration of monocytes
◦ Lipoproteins enter intima
Fatty streak
◦ Monocytes develop into macrophages
◦ Lipid-rich “foam cells” develop Atheroma
Damage to intima
◦ Liberates platelet-derived growth factor
Proliferation of smooth muscle cells Fibrous cap forms
◦ From connective tissue and low-density lipoprotein (LDL)
Fibrous cap often ruptures
◦ Thrombus
◦ Clotting cascade initiated
Pathophysiology of CAD Adhesion: Activation: Aggregation: Drugs administered to stop the process?
- Adhesion: platelets bind to receptors
- Activation: platelets change shape and activate receptors
◦ Release: thromboxane A2 and serotonin
◦ Activate glycoprotein IIb/IIIa receptors - Aggregation: platelets clump together
- Drugs administered to stop the process
◦ Aspirin
◦ Glycoprotein IIb/IIIa inhibitors
Risk Factors for CAD
Nonmodifiable factors
Modifiable
- Nonmodifiable factors Age ◦ Men > 45 years ◦ Women > 55 years Family history - Modifiable Smoking Inactivity Overweight Cholesterol ◦ High LDL ◦ Low levels of HDL Diabetes Hypertension
History for CAD
- Risk factors
- Prior hospitalizations
- Shortness of breath, chest pain
- Medications
◦ Erectile dysfunction meds if considering nitroglycerin - Psychosocial history
◦ Include stressors
Diagnostic Studies for CAD
- 12-lead electrocardiogram (ECG)
- Holter monitor
- Exercise tolerance test (stress test)
◦ Exercise to increase demand on heart
◦ Stressed via drugs (e.g., adenosine) if patient cannot
tolerate exercise
◦ Monitoring vital signs, ECG - Pharmacological stress testing Nuclear stress testing
- Chest x-ray
- Echocardiography
◦ Ultrasound to visualize cardiac structures - Transesophageal echocardiography
- Multigated blood pool study (MUGA scan)
- Positron emission tomography (PET scan)
- Cardiac magnetic resonance imaging
Cardiac Catheterization and Arteriography
- Electrophysiology study Catheter (right or left)
◦ Heart pressures (similar to PA catheter)
◦ Cardiac output - Arteriography
◦ Visualize blood vessels
Post-catheterization Care
- Bed rest; head of bed no higher than 30 degrees
- Monitor bleeding; newer collagen agents for hemostasis may be used
- Monitor pulses
- Antiplatelet drugs after the procedure (usually after interventions such as PCI)
- May be discharged in 6 to 8 hours; depends on diagnosis and procedures done in catheterization laboratory
Laboratory Tests for post cath care
- CBC ◦ Hemoglobin ◦ Hematocrit - Sodium - Potassium - Calcium - Magnesium
Cardiac Enzymes
- Troponin I and T
◦ As early as 1 hour after injury
◦ Normal values less than 0.5 mcg/L for Troponin I
◦ Normal values less than 0.1 mcg/L for Troponin T
Which value, when elevated, places the patient at lowest risk for CAD? A. Triglycerides B. Low-density lipoproteins (LDLs) C. High-density lipoproteins (HDLs) D. Very-low-density lipoproteins (VLDLs)
C. High-density lipoproteins (HDLs)
Cholesterol in CAD Categories
◦ HDL is considered good
◦ LDL is considered bad
LDL Target Levels (NIH)
- No CHD and fewer than two risk factors o160 mg/dL
- No CHD and two or more risk factors o130 mg/dL
- CAD
o<100 mg/dL
Treatment for CAD
- Diet: low cholesterol, low salt
- Exercise: aerobic
- Weight loss
- Smoking cessation
- Management of hypertension and diabetes if present - Medications: lipid-lowering agents
◦ Various types: weigh advantages and disadvantages of each
Medications for Hyperlipidemia
- HMG-CoA reductase inhibitors; slow production: most effective
◦ Statins - Bile acid resins bind and are excreted via bowel.
◦ Cholestyramine
◦ Colestipol - Ezetimibe (Zetia) blocks the absorption of cholesterol in the digestive tract.
- Nicotinic acid; inhibits LDL synthesis and increases HDL; many side effects
- Fibric acid derivatives; increase VLDL clearance
◦ Gemfibrozil - Patients carefully monitored
- Combination therapy may be needed to reach target goals
Medications Affecting Platelets
- ASA (inhibits thromboxane A2)
- Others: dipyridamole, ticlopidine, and clopidogrel
Types of Angina
1) Stable (chronic, exertional) = effort, classic
◦ T-wave inversion on ECG
◦ Treatment: rest and nitroglycerin
2) Unstable (crescendo) = more often and more severe, less relief
◦ May see ST elevation on ECG
◦ Treatment: rest and nitroglycerin; drugs affecting platelets; revascularization
3) Variant = Prinzmetal’s (vasospasms)
◦ ST elevation during pain episodes
◦ Treatment: calcium channel blockers
Angina/Chest Pain
- Myocardial ischemia: the heart’s demand for oxygen is higher than the supply
- Classic symptom
- Often midsternal
- May radiate to arms, jaw, or back
- ECG changes to the ST segment/T wave
- ischemia is depressed complete occlusion is elevated
Nursing Diagnoses for angina
- Acute chest pain related to myocardial ischemia
- Knowledge deficit related to unfamiliarity with disease processes and treatment
- Activity intolerance related to ischemic changes
Nursing Management: Angina
- Maintain cardiac output
- Pain relief
- Self-care; risk-factor modification
- Medications
- Postprocedure observation and care following cardiac catheterization, angioplasty, bypass surgery.
Patient Care Outcomes for angina
- The patient will verbalize relief of chest discomfort,
appear relaxed and comfortable, verbalize an understanding of angina pectoris and its management,
describe cardiac risk factors and strategies to reduce them, and perform activities within limits of the disease,
as evidenced by absence of chest pain or discomfort and no ECG changes reflecting ischemia.
Nursing management of the patient with angina is directed toward
A. immediate administration of nitrates.
B. assessment of history of previous anginal episodes.
C. assessment and documentation of chest pain episodes.
D. administration of prophylactic lidocaine for ventricular ectopy.
A. immediate administration of nitrates.
Acute Coronary Syndrome (ACS)
- Ischemia with myocardial cell death
- Imbalance of oxygen supply and demand
- Includes stable angina, unstable angina or acute myocardial infarction
- Causes
◦ Atherosclerosis
◦ Emboli
◦ Blunt trauma
◦ Spasm
Acute Myocardial Infarction (AMI) Types
◦ Non-ST segment elevation (NSTEMI)
◦ ST segment elevation (STEMI)
Collateral circulation (go around it)
Assessment of AMI
Midsternal chest pain ◦ Severe, crushing, and squeezing pressure ◦ May radiate ◦ Unrelieved with nitrates - Pale and diaphoretic - Dyspnea, tachypnea, and/or hypotension Syncope - Feeling of impending doom - Nausea and vomiting - Dysrhythmias
Diagnosis of AMI
- Signs and symptoms
◦ Often atypical symptoms in women - 12-lead:
◦ ST elevation followed by Q wave (Q-wave myocardial infarction)
◦ ST depression (non–Q-wave myocardial infarction) - Elevated serum troponin
◦ Troponin I ◦ Troponin T
Which finding on the ECG is most conclusive for infarction? A. Q waves B. Inverted T waves C. Tall, peaked T waves D. ST-segment depression
Which finding on the ECG is most conclusive for infarction? A. Q waves B. Inverted T waves C. Tall, peaked T waves D. ST-segment depression
Nursing Diagnoses for ACS
- Acute Chest Pain
- Poor Tissue Perfusion
