Chronic Structural Heart Disorders - Chapter 40 - 5th

Overview of Valvular Heart Disease

  • The heart has four valves:

    • Atrioventricular (AV) valves: Mitral & Tricuspid

    • Semilunar valves: Aortic & Pulmonic

  • Types of Valve Dysfunction:

    • Stenosis: Narrowed valve opening restricts blood flow.

    • Regurgitation: Valve fails to close completely, causing backward blood flow.

Mitral Valve Disorders

Mitral Valve Stenosis

  • Cause: Most commonly due to rheumatic heart disease.

  • Pathophysiology:

    • Decreased left atrial to left ventricular blood flow.

    • Increased left atrial pressure, pulmonary hypertension, and risk for atrial fibrillation.

  • Clinical Manifestations:

    • Exertional dyspnea, loud S1, diastolic murmur, fatigue, palpitations.

    • Hoarseness, hemoptysis, stroke risk.

Mitral Valve Regurgitation (MR)

  • Causes: MI, rheumatic heart disease, mitral valve prolapse (MVP), infective endocarditis (IE).

  • Pathophysiology:

    • Acute MR: Pulmonary edema, cardiogenic shock.

    • Chronic MR: Left atrial enlargement, LV dilation, hypertrophy, decreased CO.

  • Clinical Manifestations:

    • Acute: Thready pulses, cool extremities.

    • Chronic: Fatigue, weakness, dyspnea, orthopnea, peripheral edema, S3, murmur.

Mitral Valve Prolapse (MVP)

  • Cause: Genetic link; confirmed with echocardiography.

  • Pathophysiology: Leaflets prolapse into left atrium during systole.

  • Clinical Manifestations:

    • Most asymptomatic, but 10% develop symptoms.

    • Murmur, palpitations, syncope, chest pain unresponsive to nitrates.

  • Management: Beta-blockers, healthy diet, avoiding stimulants.

Aortic Valve Disorders

Aortic Valve Stenosis (AS)

  • Causes: Congenital (young), degenerative (older adults), or rheumatic fever.

  • Pathophysiology:

    • Obstructed blood flow from LV → aorta → LV hypertrophy.

    • Leads to decreased CO, pulmonary hypertension, and HF.

  • Clinical Manifestations:

    • Classic Triad: Angina, syncope, exertional dyspnea.

    • Murmur: Systolic, radiates to carotids, prominent S4.

    • Caution: Nitroglycerin use can worsen chest pain.

Aortic Valve Regurgitation (AR)

  • Causes:

    • Acute: Infective endocarditis (IE), trauma, aortic dissection → life-threatening emergency.

    • Chronic: Rheumatic heart disease, congenital, connective tissue disorders.

  • Pathophysiology: Backflow from aorta → LV, causing LV dilation and hypertrophy.

  • Clinical Manifestations:

    • Acute: Severe dyspnea, hypotension, cardiogenic shock.

    • Chronic: Asymptomatic for years, then exertional dyspnea, orthopnea, angina, water-hammer pulse, S3 or S4.

Tricuspid & Pulmonic Valve Disorders

Tricuspid Valve Stenosis

  • Cause: Rheumatic fever.

  • Clinical Manifestations: Fluttering neck discomfort, fatigue.

Pulmonic Valve Disorders

  • Pulmonary Regurgitation:

    • Causes: Pulmonary hypertension, congenital disease, surgical repair of Tetralogy of Fallot (TOF).

    • Can lead to right ventricular dilation.

  • Pulmonic Stenosis:

    • Almost always congenital.

    • Causes right ventricular hypertrophy.

    • Often asymptomatic until adulthood.

Diagnostic Studies for Valvular Disease

  • Echocardiography (3D, TEE, Doppler).

  • Chest X-ray & ECG.

  • Cardiac catheterization (hemodynamic assessment).

Management & Treatment of Valvular Disease

Conservative Management

  • Prevent worsening of HF, thromboembolism, and infective endocarditis.

  • Medications:

    • Heart failure drugs: Vasodilators (ACE inhibitors), beta-blockers, digoxin, diuretics.

    • Atrial fibrillation management: Calcium channel blockers, anticoagulants.

  • Lifestyle Modifications: Low-sodium diet, exercise.

Interventional & Surgical Therapy

  • Percutaneous Transluminal Balloon Valvuloplasty (PTBV):

    • Used for mitral, tricuspid, pulmonic, and aortic stenosis.

    • Balloon catheter inserted via femoral artery to separate valve leaflets.

  • Valve Surgery:

    1. Valve Repair (preferred):

      • Commissurotomy (valvulotomy).

      • Valvuloplasty, Annuloplasty.

    2. Valve Replacement:

      • Mechanical Valves: Durable but require lifelong anticoagulation (risk of thromboembolism).

      • Biologic Valves (tissue): Shorter lifespan but no anticoagulation needed.

Transcatheter Aortic Valve Replacement (TAVR)

  • Minimally invasive option for severe AS.

  • Transfemoral approach used.

Nursing Management & Implementation

Assessment

  • Subjective Data:

    • Medical history (IV drug use, rheumatic fever, prior infections).

    • Symptoms: Fatigue, palpitations, activity intolerance, dizziness, dyspnea, angina.

  • Objective Data:

    • Physical Exam: Fever, diaphoresis, cyanosis, clubbing, crackles, murmur.

    • Vitals & Cardiac Findings: Dysrhythmias, water-hammer pulse, thready peripheral pulses.

    • Liver Enlargement & Fluid Retention: Hepatomegaly, ascites, weight gain.

Common Clinical Problems

  1. Impaired cardiac function.

  2. Fatigue.

  3. Fluid imbalance.

Nursing Goals & Planning

  • Maintain normal heart function.

  • Improve activity tolerance.

  • Educate patient on disease management.

Health Promotion & Patient Education

  • Prevent streptococcal infections (early antibiotic treatment).

  • Prophylactic antibiotics for patients with prior history.

  • Lifestyle modifications:

    • Avoid tobacco.

    • Exercise but avoid fatigue-inducing activities.

  • Ongoing cardiac monitoring.

Medication & Anticoagulation Therapy

  • Monitor INR in patients with mechanical valves.

  • Education on drug actions & side effects.

  • When to Seek Medical Care: Signs of HF, infection, or bleeding.

  • Medical Alert ID for valve replacement patients.

Expected Outcomes

  • Maintain adequate perfusion and fluid balance.

  • Achieve optimal activity level.

  • Understand disease process and preventive care.