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Complex Perfusion Lecture Notes

Introduction to Cardiac Anatomy and Physiology

  • Background and foundational knowledge in cardiac anatomy is necessary for NUR 265.
  • Review of anatomy is critical and incorporated in quizzes at the beginning and end of each week.

Surface Anatomy of the Heart

  • Anatomy Overview:
    • Right pulmonary artery
    • Superior vena cava
    • Aortic valve
    • Right atrium
    • Tricuspid valve
    • Inferior vena cava
    • Left pulmonary artery
    • Left atrium
    • Mitral valve
    • Left ventricle
    • Right ventricle
  • Surface Views:
    • Anterior and posterior views of the heart show the location and relationship between various structures.
    • Major blood vessels and their paths:
    • Superior vena cava: drains blood from the upper body to the right atrium.
    • Inferior vena cava: drains blood from the lower body to the right atrium.
    • Pulmonary arteries transport unoxygenated blood to the lungs.
    • Pulmonary veins bring oxygenated blood from the lungs to the left atrium.

Coronary Arterial System

  • Key Components:
    • Right main coronary artery
    • Left main coronary artery
    • Circumflex coronary artery
    • Left anterior descending coronary artery
    • Posterior descending coronary artery
    • Importance of peripheral branches

Key Cardiac Terms to Remember

  • Cardiac Output: Amount of blood the heart pumps in a minute.
  • Preload: Volume of blood in the ventricles at the end of diastole.
  • Stroke Volume: Amount of blood pumped by the heart with each beat.
  • Afterload: Resistance the heart must overcome to eject blood.
  • Systole: Contraction phase of the heart.
  • Diastole: Relaxation phase of the heart.

Ejection Fraction

  • Definition: Measurement of the percentage of blood that is ejected from the heart each time it contracts.
  • Normal Range: 60-75%.

Physical Assessment of Cardiac Function

  • Conduct a complete physical assessment focusing on:
    • Neuro assessment
    • Cardiac evaluation (pulse strength, heart rate, blood pressure)
    • Respiratory function
    • GI and GU assessment
    • Skin condition

Hemodynamics

  • Invasive Monitoring: Used to acquire critical information concerning:
    • Vascular capacity
    • Blood volume
    • Pump effectiveness
    • Tissue perfusion
    • Direct measurement of pressures in the heart and major vessels.

Hemodynamic Monitoring Components

  • Measurements of:
    • Heart Rate
    • Blood Pressure and MAP (Mean Arterial Pressure)
    • Central Venous Pressure (CVP)
    • Pulmonary Artery Pressures
    • Systemic Vascular Resistance (SVR)
    • Pulmonary Vascular Resistance (PVR)
    • Cardiac Output (CO)
    • Stroke Volume

Catheter Types and Functions

  • Triple-lumen Venous Catheter:
    • Used for fluid infusion and monitoring central venous pressure (CVP).
    • Normal CVP is 3-8 mm Hg.
  • Swan-Ganz Catheter:
    • Monitors fluid status and pressures inside the heart and lungs.

Hemodynamic Values

  • Mean Arterial Pressure (MAP): 70-90 mmHg
  • Central Venous Pressure (CVP): 3-8 mmHg
  • Pulmonary Artery Pressure (PAP):
    • Systolic: 15-26 mmHg
    • Diastolic: 5-15 mmHg
  • Pulmonary Artery Wedge Pressure (PAWP): 4-12 mmHg
  • Cardiac Output (CO): 3-6 L/min

Cardiac Function Assessment

  • Testing Methods:
    • Stress Tests (nuclear imaging)
    • Echocardiogram
    • Cardiac Catheterization

Identifying Cardiac System Issues

  • Major categories of cardiac issues include:
    • Volume
    • Heart function
    • Electrical signals
    • Vascular structures

Coronary Arteries Overview

  • Importance: The heart muscle requires blood supplied by coronary arteries for oxygen and nutrient delivery.
    • Ischemia can occur if coronary vessels are blocked.
    • Acute Coronary Syndrome leading to myocardial infarction (heart attack).

Acute Coronary Syndrome (ACS)

  • Coronary Artery Disease (CAD):
    • Characterized by plaque buildup in coronary arteries, leading to reduced blood flow to the myocardium.
    • Major risk: undiagnosed angina can escalate to acute myocardial infarction (AMI).
    • Leading cause of death across all demographics in the U.S.

Etiology and Risk Factors for CAD

  • Metabolic Syndrome Components:
    • Age: Men > 65, Women > 72
    • Hypertension: BP > 130/85 mmHg
    • Low HDL levels < 40 mg/dL
    • Increased triglycerides > 150 mg/dL
    • Elevated fasting blood glucose > 100 mg/dL
    • Large waist circumference > 40 inches
    • Medications for the above conditions
  • Lifestyle Factors:
    • Smoking, lack of physical activity, obesity, stress, diabetes

Clinical Manifestations of CAD

  • Symptoms of Acute Myocardial Infarction (AMI):
    • Chest pain, possible radiation to arm(s), neck, jaw, or back.
    • Syncope, palpitations, edema, epigastric discomfort, diaphoresis, dyspnea, orthopnea.
    • Women may present vague symptoms, including prolonged fatigue.

Medications for CAD

  • Nitrates:
    • Nitroglycerin (sublingual, spray, transdermal)
    • Isosorbide dinitrate
  • Beta Blockers:
    • Reduce heart rate, blood pressure, and cause vasodilation (e.g., Carvedilol, Metoprolol).
  • Antiplatelet Agents:
    • Aspirin and Clopidogrel (Plavix).
    • Monitor for bleeding, gastric irritation, and diarrhea.

Management of Myocardial Ischemia

  • Due to plaque occlusion, ischemia causes:
    • Angina, or chest pain due to insufficient blood flow.

Types of Angina

  • Chronic Stable Angina: Relieved by rest/medication.
  • Unstable Angina: Severe limitations, not relieved by rest.
  • Prinzmetal Angina: Occurs at rest, often due to vascular spasm.

Treatment Strategies for Angina

  • Priority Nursing Actions:
    • Stop all activity, rest, and administer medications and oxygen as needed.

Diagnostic Tests for CAD

  • Tests include:
    • ECG, chest X-ray, stress test, echocardiography, cardiac catheterization, MRI, CT angiography, electrophysiology studies.

Risk Factors for Coronary Artery Disease (CAD)

  • Key Factors:
    • Increased heart rate and blood pressure leading to plaque rupture.
    • Resultant thrombus formation can lead to partial or complete occlusion.

Cardiac Muscle Issues

  • Conditions such as heart failure and myocardial infarction (MI) impact cardiac output and perfusion.

Acute Myocardial Infarction (AMI)

  • Characterized by necrotic areas in the myocardium due to sudden occlusion of coronary artery.
  • Consequences: Impairs heart function, diminishes cardiac output, can be lethal.

Risk Factors for AMI

  • Modifiable Factors:
    • Smoking, diet, hypertension, obesity, diabetes, stress.
  • Non-Modifiable Factors:
    • Gender, family history, menopause.

Clinical Manifestations of AMI

  • Chest pain lasting 30+ minutes, potentially relieved by nitroglycerin.
  • Atypical presentations, especially in women (e.g., fatigue, nausea).

Diagnostic Procedures for AMI

  • Troponin I and T: Serum levels increase within a few hours of chest pain; correlation with myocardial damage.
  • Other Lab Tests:
    • CK-MB, complete blood count, electrolytes, glucose.

Treatment Protocol for Acute MI

  • Immediate Actions:
    • Obtain ECG, administer oxygen, medications (aspirin, nitroglycerin, morphine).
  • Medications:
    • Beta-blockers, heparin, ACE inhibitors.

Thrombolytic Therapy

  • Initiation within 30 minutes of ED admission to restore blood flow by dissolving thrombi.
  • Contraindications: Recent surgery, stroke history.

Stent Care and Post-op Management

  • Requirement for long-term medications to prevent stent occlusion (e.g., clopidogrel).
  • Post-op Assessment: Includes bedrest and continuous vital signs monitoring.

Indicators of Successful Reperfusion

  • Normalization of ECG changes, relief of chest pain, elevated CK-MB peak shortly after procedure.

Evidence-Based Emergency Care for AMI

  • Ensuring timely interventions with medications and monitoring during hospitalization to enhance recovery outcomes.

Medications for Heart Failure

  • ACE Inhibitors: Lower blood pressure and improve cardiac efficiency (e.g., Captopril).
  • Beta Blockers: Slow heart rate and decrease blood pressure (e.g., Atenolol).
  • Nitrates: Relieves workload on heart through vasodilation.

Complications of Myocardial Infarction

  • Common complications include:
    • Dysrhythmias, heart failure, cardiogenic shock, and structural changes like ventricular remodeling.

Cardiomyopathy

  • Types: Dilated, Hypertrophic, Restrictive, Arrhythmogenic Right Ventricular.
  • Treatment strategies coincide with heart failure management.

Acute Cardiogenic Pulmonary Edema

  • Results from heart failure leading to fluid accumulation in the alveoli affecting gas exchange.
  • Management: Address underlying causes, provide oxygen, and pharmacological support.

Infective Endocarditis

  • Risk Factors and Pathophysiology: Associated with IV drug use and valve replacements, leads to potential valve destruction.
  • Management: IV antibiotics and supportive care.

Valvular Heart Disease

  • Types: Stenosis and regurgitation impacting blood flow efficiency.
  • Common Valve Disorders: Mitral and aortic valve issues.

Valve Diagnostic and Treatment Options

  • Diagnostics: Echocardiography plays a crucial role in assessing valve function.
  • Interventions: Mechanical or biological valve replacement may be necessary.

Pericarditis and Cardiac Tamponade

  • Pathophysiology: Fluid accumulation limiting heart function leading to decreased cardiac output.
  • Symptoms and Management: Treatment of underlying causes and monitoring for signs of tamponade.

Aneurysms and Aortic Dissection

  • Therapeutic Approach: Recognizing symptoms and conducting timely interventions to prevent rupture and treat complications.
    • Management may involve surgery or monitoring depending on size.

Knowledge Checkpoints

  • Practice Questions evaluating understanding of material.
  • Essential Focus: Therapeutic priorities, diagnostics, complications, and treatment modalities for various cardiovascular conditions.