Book Chapter 24

ATHEROSCLEROSIS

  • Definition of Arteriosclerosis

    • Arteriosclerosis is the thickening, loss of elasticity, and calcification of arterial walls.

    • Occurrence: Common with aging.

  • Definition of Atherosclerosis

    • Atherosclerosis is the formation of plaque in the arteries.

    • Conditions may begin in early childhood and progress without symptoms through adulthood.

    • Major cause of coronary heart disease (CHD), also known as coronary artery disease (CAD).

  • Word Building

    • arteriosclerosis: arterio—artery + sklerosis—hardness

Pathophysiology

  • Atherosclerosis Process

    • A multistep process affecting the inner lining of the artery.

    1. Injury to Endothelial Cells: Inflammation and immune response occur.

    2. Smooth Muscle Cell Proliferation: Growth of smooth muscle cells secretes collagen and fibrous proteins.

    3. Plaque Formation: Lipids, platelets, and clotting factors accumulate, forming plaque, composed of:

    • Smooth muscle cells

    • Fibrous proteins

    • Cholesterol-laden foam cells

    1. Capsule Development: Plaque develops a fibrous cap that can undergo calcification.

    2. Tear or Rupture of Fibrous Cap: Leads to formation of a blood clot, which can cause:

    • Complete blockage of the coronary artery

    • Occlusion in smaller arteries, leading to ischemia distal to occlusion

  • Figure 24.1: Cross-section of a normal coronary artery vs. atherosclerosis.

Etiology

  • Risk Factors for Atherosclerosis

    • Divided into two categories:

    1. Non-modifiable:

      • Age: Increased incidence after age 50.

      • Ethnicity: Higher incidence in Black Americans.

      • Gender: Men have higher incidence; women post-menopause.

      • Genetics: Family history of factors like hyperlipidemia.

    2. Modifiable/Controllable:

      • Diabetes Mellitus: Increases hypertension, obesity, and blood lipids.

      • Hypertension: Increases myocardial oxygen demand.

      • Cholesterol Levels: Levels over 200 mg/dL raise CAD risk.

      • LDL and Apo B: High levels infiltrate arterial walls.

      • Homocysteine: Elevated levels increase CAD risk; foods with folic acid can lower these levels.

      • Alcohol: Raises blood pressure and triglycerides, causes arrhythmias.

      • Obesity: Elevates heart workload and risk of other conditions.

      • Sedentary Lifestyle: Contributes to obesity and hypertension.

      • Emotional Stress: Raises heart workload and hypertension risk.

      • Tobacco Use: Increases myocardial oxygen demand, decreases HDL levels.

Diagnostic Tests

  • Cholesterol Levels:

    • Total cholesterol over 200 mg/dL increases CAD risk.

    • LDL and HDL levels evaluated; high Lp(a) cholesterol indicates premature CAD.

    • Excellent predictor of MI risk: LDL particle number, measured through apolipoprotein B.

    • C-reactive protein (CRP): Indicates low-grade inflammation in blood vessels.

    • Blood glucose levels impact atherosclerosis risk.

    • Radiological studies visualize narrowed or occluded vessels.

  • Table 24.2: Diagnostic Tests for Atherosclerosis

Therapeutic Measures

  • Maintain a healthy lifestyle and medication use to control atherosclerosis.

  • Diet: Adhere to a heart-healthy diet (DASH eating plan).

  • Smoking Cessation: Greater CAD risk in smokers; risk correlates with cigarette quantity.

    • Effects of secondhand and thirdhand smoke must be communicated to patients.

  • Exercise:

    • Raises HDL, lowers insulin resistance.

    • Develops collateral circulation over time.

  • Medications:

    • Statins: Reduce LDL by inhibiting cholesterol synthesis.

    • E.g. Atorvastatin, Rosuvastatin

    • Monitoring: Liver function and signs of rhabdomyolysis.

    • Fibrates: Lower triglycerides.

    • E.g. Gemfibrozil, Fenofibrate

    • Niacin: Prevents conversion of fats, rarely used due to side effects.

    • Cholesterol Absorption Inhibitors: Decrease LDL and increase HDL.

CORONARY ARTERY DISEASE (CAD)

  • Definition: CAD causes obstruction of blood flow through coronary arteries to heart muscle cells, usually due to atherosclerosis.

  • Prevention: Focus on risk factor modification and lifestyle changes.

    • Evidence-based initiatives for cardiovascular health include managing cholesterol, blood pressure, and smoking cessation.

Angina Pectoris

  • Definition: Chest pain due to ischemia from reduced coronary artery blood flow.

  • Types of Angina:

    • Stable Angina: Predictable pattern, relieved by rest or medication.

    • Vasospastic Angina: Caused by spasm, often cyclical, more severe.

    • Microvascular Angina: Severe pain from smallest artery spasms.

Management and Treatment of Angina

  • Diagnostics: ECG, stress tests, echocardiography, CT/MRI, coronary angiography.

  • Medications: Nitrates, beta blockers, calcium channel blockers.

    • Nitrate Use: NGS as first-line treatment; important to avoid drug interactions with erectile dysfunction meds.

  • Nursing Considerations: Monitor for adherence and complications; education on lifestyle changes.

Myocardial Infarction (MI)

  • Definition: Death of heart muscle due to a sudden blockage.

  • Pathophysiology: Ischemia evolves over time, leading to necrosis if not treated.

  • Signs and Symptoms: Chest pain, possible radiation, shortness of breath, nausea.

  • Tests: Troponins, ECG changes, imaging methods.

Therapeutic Measures for MI

  • Acute Treatment: Medications (antiplatelets, anticoagulants, thrombolytics), surgical interventions (angioplasty, stenting, CABG).

  • Nursing Considerations: Monitor for complications, including arrhythmias, cardiogenic shock, and myocardial function.

Peripheral Vascular Disease (PVD)

  • Definition and Types: Classified as arterial or venous disorders.

  • Pathophysiology: Caused by obstruction of blood flow, which can result in ischemia.

  • Diagnosis and Therapeutic Measures: Assess for claudication, monitor blood flow parameters, and provide lifestyle adjustments.

Aneurysms

  • Definition: A bulge in the arterial wall due to weakness.

  • Signs and Symptoms: Often asymptomatic; classic sign includes abdominal pain or pulsating mass.

  • Risk Factors: Atherosclerosis, hypertension, smoking.

Varicose Veins and Venous Insufficiency

  • Overview: Chronic condition causing pooling of blood; related to valve dysfunction.

  • Treatment: Elevation, compression therapy, and lifestyle changes to promote flow.

Nursing Considerations

  • Patient Education: Teach patients about risk factor management and medication adherence.

  • Surgical Preparedness: Care protocols for patients undergoing vascular surgeries.

  • Collaboration: Work with healthcare teams for comprehensive patient management.

Etiology of Coronary Artery Disease (CAD)

  • CAD is primarily caused by atherosclerosis, leading to the obstruction of blood flow through coronary arteries.

  • Risk Factors:

    1. Non-modifiable:

    • Age, with increased incidence after age 50.

    • Ethnicity, higher in Black Americans.

    • Gender, men are more affected; women post-menopause.

    • Genetics, family history of hyperlipidemia.

    1. Modifiable:

    • Diabetes Mellitus, hypertension, high cholesterol levels, obesity, sedentary lifestyle, smoking, and emotional stress.

Signs and Symptoms (S/S) of CAD

  • Angina pectoris (chest pain due to ischemia).

  • Shortness of breath.

  • Fatigue upon exertion.

Therapeutic Measures for CAD

  • Lifestyle Modifications:

    • Heart-healthy diet (e.g., DASH plan).

    • Smoking cessation.

    • Regular exercise.

  • Medications:

    • Statins (e.g., Atorvastatin, Rosuvastatin). monitor liver function, ALT, AST, AGT. Get baseline before starting medication, muscle pain, take in the evening or at night.

    • Antiplatelets (e.g., Clopidogrel).

    • Antihypertensives.

    • Fibrates - Hypoglycemia effects increases, monitor

    • Nisain (Nispan) Redness/ burning senstation in the face

Angina Pectoris

  • Etiology: Reduced coronary artery blood flow often due to atherosclerosis.

  • S/S: Predictable chest pain relieved by rest or medication (stable angina), severe pain from artery spasms (vasospastic angina).

  • Therapeutic Measures: Nitrates, beta blockers, calcium channel blockers.

Myocardial Infarction (MI)

  • Etiology: Sudden blockage of blood flow due to a thrombus.

  • S/S: Severe chest pain, shortness of breath, nausea.

  • Therapeutic Measures: Medications (antiplatelets like Clopidogrel and thrombolytics like TNKase, Retavase), surgical interventions (angioplasty, CABG).

If pain reduces when taking Nitro it will not be a MI consider an angina attack rather than an MI

Diagnostic Tests for CAD

  • Blood tests for cholesterol and glucose levels.

  • ECG to identify ischemic changes.

  • Imaging studies (angiography).

Nursing Care for CAD and MI

  • Educate patients on lifestyle changes and medication adherence.

  • Assess for chest pain and monitor risk factors.

  • Post-MI care includes monitoring for arrhythmias and myocardial function.

Medications to Lower Lipid Levels (Table 24.3)

  1. Atorvastatin: Reduces LDL and overall cholesterol.

  2. Rosuvastatin: Similar lipid-lowering effects.

  3. Simvastatin: Effective in lowering cholesterol.

  4. Fenofibrate: Primarily lowers triglycerides.

Medications for Angina Pectoris (Table 24.4)

  1. Clopidogrel/Aspirin: Antiplatelet agent.

  2. Nitroglycerin: Nitrate for chest pain relief. Avoid erectile dysfunction medications, can give in a four hour window, the medication can lower the blood pressure. this creates a double wammy.

  3. Nitro-Bid: Additional nitrate for angina.

  4. Isosorbide dinitrate: Long-acting nitrate.

  5. Beta-Blocker: ends in olol, decreases heart rate,

Surgical Procedures for Myocardial Infarction

  • Angioplasty: Minimally invasive procedure to widen blocked arteries.

  • Coronary Artery Bypass Grafting (CABG): Surgical procedure to create a new route for blood flow. 7-10 days after initial insult

Peripheral Vascular Disorders

  1. Peripheral Artery Disease (PAD): Reduced blood flow to extremities, causing claudication.

  2. Raynaud's Disease: Spasms of small arteries reduce blood flow, causing color changes.

  3. Buerger's Disease: Blood vessel inflammation in arms and legs, linked to smoking.

  4. Aneurysms: Bulges in arteries potentially leading to rupture.

  5. Varicose Veins: Veins enlarge due to valve dysfunction, causing blood pooling.

  6. Venous Insufficiency: Inadequate venous return, often causing swelling and pain.

Nursing Care for Peripheral Vascular Disorders

  • Assessment of peripheral circulation and education on risk factor management.

  • Support lifestyle changes to improve vascular health.

  • Post-surgical care for patients undergoing vascular interventions.