Conditions of Circulatory system

Subtopic:

Rheumatic heart disease

  • Rheumatic heart disease is a condition where the heart valves have been permanently harmed due to rheumatic fever.
  • Rheumatic Heart Disease can also be described as the long-term consequence of Rheumatic Fever, affecting all the heart’s layers and leading to significant heart-related problems.
  • So what is Rheumatic Fever?
  • Rheumatic Fever is an immune system disorder triggered by a preceding streptococcal infection. It’s a systemic inflammatory illness that can affect various parts of the body, most notably the heart, joints, brain, skin, and the tissue beneath the skin.
  • The saying goes, ‘rheumatism licks the joint, but bites the whole heart’.
Causes/Etiology of Rheumatic Heart Disease
  • Infection: The damage to the heart can begin shortly after an untreated streptococcal throat infection, commonly known as strep throat, or scarlet fever. The underlying cause of this process is rheumatic fever, which is triggered by group A beta-hemolytic streptococci, specifically Streptococcus pyogenes.

  • The heart valves can become inflamed, and this inflammation can lead to scarring over time.
    This scarring can cause the valve to become too narrow (stenosis) or to leak (regurgitation or insufficiency), making it more difficult for the heart to pump blood effectively.
    The mitral valve and the aortic valve are the most frequently affected, though it’s possible for all four heart valves to be involved. This damage can take many years to manifest and can eventually lead to heart failure.

Pathophysiology of Rheumatic Heart Disease.
  • The process begins with a strep throat infection caused by Group A Beta-hemolytic streptococci. If this strep throat is left untreated, it can progress to rheumatic fever several weeks after the initial sore throat has resolved. It’s important to note that only infections of the pharynx (the throat) have been shown to initiate or reactivate rheumatic fever.
  • Over a period of months to years following an episode of rheumatic fever, severe scarring of the heart valves can develop. Subsequent episodes of rheumatic fever can cause further damage to the heart valves. The mitral valve is the most commonly and severely affected valve (in 65-70% of patients), followed by the aortic valve. This progressive damage can ultimately lead to heart failure.
Clinical features of Rheumatic Fever.

The signs and symptoms of Rheumatic Fever can include:

  • Fever: Elevated body temperature (39 degrees Celsius or higher).

  • Swollen, tender, red and extremely painful joints: Often affecting the knees and ankles, with the pain moving from one joint to another (Migrating Polyarthritis).

  • Nodules: Painless lumps under the skin.

  • Shortness of breath and chest discomfort.

  • Uncontrolled movement of arms, legs or facial muscles (Sydenham’s chorea).

  • General weakness.

  • Carditis: Inflammation of the heart, presenting with chest pain, dyspnea (shortness of breath), and palpitations (awareness of heartbeats).

Clinical features of Rheumatic Heart Disease.

The long-term effects of Rheumatic Fever on the heart manifest as:

  • Carditis: Inflammation affecting different layers of the heart:

    • Pericarditis: Inflammation of the outer lining of the heart (pericardium).

    • Myocarditis: Inflammation of the heart muscle (myocardium).

    • Endocarditis: Inflammation of the inner lining of the heart and heart valves (endocardium).

  • Polyarthritis: Acute pain and swelling in the joints, starting in one joint and moving to others (migratory polyarthritis), less commonly seen in children.

  • Chorea: Involuntary, irregular, and unpredictable muscle movements (Sydenham’s chorea).

  • Erythema marginatum: A distinctive, long-lasting reddish rash that typically starts on the trunk or arms as flat spots (macules). These spots spread outwards, clearing in the center to form rings. These rings continue to expand and merge with other rings, creating a snake-like pattern.

  • Subcutaneous nodules: Painless, firm lumps made of collagen fibers, usually found over bones or tendons. Common locations include the back of the wrist, the outside of the elbow, and the front of the knees.

Diagnosis of Rheumatic Heart Disease

Diagnosing Rheumatic Heart Disease involves:

  • Assessing for a history of strep throat infection: Individuals with rheumatic heart disease will typically have had a recent or past strep throat infection. A throat culture or blood test can be used to detect the presence of streptococcus bacteria.

  • Auscultation: Listening to the heart with a stethoscope may reveal murmurs or a rub, sounds caused by blood leaking around damaged heart valves.

  • In addition to a complete medical history and physical examination, tests used to diagnose rheumatic heart disease may include:

    • Echocardiogram (cardiac echo): An ultrasound of the heart to visualize the heart valves and heart muscle function.

    • Electrocardiogram (ECG): A recording of the heart’s electrical activity. In patients with rheumatic heart disease, ECG findings may indicate valve insufficiency and ventricular dysfunction.

    • Cardiac MRI and Chest Radiography: Imaging techniques that can reveal cardiomegaly (enlarged heart), pulmonary congestion, and other signs consistent with heart failure in individuals with rheumatic fever.

    • Blood tests: Measuring levels of C-reactive protein and erythrocyte sedimentation rate (ESR). These markers are typically elevated in individuals with rheumatic fever due to the inflammatory nature of the disease.

Modified JONES
(A) Key Diagnostic Criteria

These are the primary guidelines for diagnosing Rheumatic Heart Disease, known as the Jones Criteria.

  • J – Joint Inflammation (Migratory Polyarthritis): Characterized by temporary, shifting joint pain and swelling. Typically begins in larger joints like knees and ankles, then moves upwards to other joints.

  • O – Carditis: (“O” resembles a heart) Indicates heart involvement, specifically inflammation of the heart muscle (myocarditis).

  • N – Subcutaneous Nodules: Painless, firm lumps that develop under the skin.

  • E – Erythema Marginatum: A distinctive rash featuring ring-shaped, reddish lesions. These lesions can appear on the trunk and limbs and may merge to form snake-like patterns.

  • S – Sydenham Chorea: A delayed neurological manifestation, characterized by involuntary, jerky, and aimless movements, often described as twitch-like.

(B) Supporting Diagnostic Criteria

These are secondary criteria that support the diagnosis when combined with major criteria or other minor criteria.

  • C – Elevated CRP (C-Reactive Protein): Indicates increased inflammation in the body. A level above 3mg/dl is considered elevated.

  • A – Arthralgia: Joint pain without objective signs of inflammation (painful joints, but not swollen or red).

  • F – Fever: Elevated body temperature, typically greater than 38.5 degrees Celsius (101.3 degrees Fahrenheit).

  • E – Elevated ESR (Erythrocyte Sedimentation Rate): Another marker of inflammation in the body. A level above 60mm/hr is considered elevated.

  • P – Prolonged PR Interval: Observed on an electrocardiogram (ECG), suggesting a delay in electrical conduction between the atria and ventricles of the heart. This interval reflects the time it takes for electrical signals to travel from the upper chambers (atria) to the lower chambers (ventricles) of the heart.

  • A – Prior History of Rheumatic Fever: A previous occurrence of rheumatic fever is a significant risk factor.

  • L – Leukocytosis: Elevated white blood cell count, often indicative of infection or inflammation.

Diagnostic Confirmation

Rheumatic Heart Disease diagnosis requires evidence of a preceding Group A Streptococcal infection PLUS:

  • Two Major Criteria

    OR

  • One Major Criterion and Two Minor Criteria

(C) Evidence of Preceding Group A Streptococcal Infection

This is crucial for confirming the link to rheumatic fever and includes:

  • Positive Throat Culture: Laboratory confirmation of Group A Streptococcus bacteria in a throat swab.

  • Rapid Antigen Detection Test: Quick test to detect Group A Streptococcus antigens in a throat swab.

  • Elevated Streptococcal Antibody Titers: Blood tests showing increased levels of antibodies produced by the body in response to Group A Streptococcus. Common tests include Anti-Streptolysin O (ASO or ASLO) and Anti-DNase B.

  • Recent Scarlet Fever: A characteristic rash associated with Group A Streptococcal infection.

Investigations for Rheumatic Heart Disease

  • Throat Swab/Culture: To detect Group A Streptococcus bacteria.

  • Rapid Antigen Detection Test: For quick identification of Group A Streptococcus.

  • Anti-streptococcal Antibody Titers: Blood tests to assess the body’s immune response to streptococcal infection.

  • Complete Blood Count (CBC): To assess white blood cell count and other blood parameters.

  • Physical Examination: To listen for heart murmurs (abnormal heart sounds) and assess heart rhythm irregularities.

  • Chest X-ray: May reveal heart enlargement (cardiomegaly) or fluid buildup in the lungs (congestion).

  • Echocardiogram/Doppler Echocardiography: Ultrasound of the heart to visualize heart structures, detect valve problems (valvular dysfunction), and fluid around the heart (effusion).

Management of Rheumatic Heart Disease

Treatment strategies depend on the extent of heart valve damage. Severe cases may require valve repair or replacement surgery. Medical management focuses on:

  1. Preventing and Eradicating Infection

  2. Optimizing Cardiac Output

  3. Enhancing Patient Comfort

1. Preventing and Eradicating Infection

  • Primary Prevention: The most effective approach is preventing rheumatic fever itself by promptly treating Group A Streptococcal throat infections with antibiotics.

  • Secondary Prophylaxis:

    • Intramuscular Benzathine Penicillin: Administered every 4 weeks (0.6-1.2 million units). In high-risk areas for rheumatic fever, it may be given every 3 weeks.

    • Duration of Prophylaxis: Patients with rheumatic fever who developed carditis and valve damage require long-term antibiotic prophylaxis, typically for at least 10 years or until age 40. Patients with rheumatic fever without valve damage may not need long-term prophylaxis.

2. Optimizing Cardiac Output

  • Anti-inflammatory Medications: To manage acute inflammation.

    • Salicylates (Aspirin): Effective in reducing most rheumatic fever symptoms except chorea, when used in anti-inflammatory dosages.

    • Corticosteroids (Prednisone): Added to salicylate therapy if there is moderate to severe carditis, indicated by heart enlargement, advanced heart block, or congestive heart failure.

  • Analgesics (Paracetamol/Acetaminophen): For pain relief, paracetamol is often preferred over opioid pain relievers for arthritis pain.

  • Anticonvulsants (Valproic Acid, Carbamazepine): Prescribed for severe involuntary movements associated with Sydenham chorea.

  • Antibiotics (Penicillin, Erythromycin): To eliminate any remaining Group A Streptococcus bacteria.

  • Surgical Intervention: May be necessary if heart failure persists despite medical treatment. Surgery may address valve problems to reduce valve leakage. A significant percentage of acute rheumatic fever patients may develop mitral stenosis later in life.

  • Dietary Recommendations: Nutritious diet without specific restrictions unless congestive heart failure is present. In CHF, a sodium and fluid-restricted diet is advised. Potassium supplementation might be needed due to corticosteroid and diuretic use.

  • Activity Management:

    • Initial Bed Rest: Followed by gradual increase in indoor activity before returning to normal activities.

    • Activity Restriction: Full activity is restricted until the PR interval on ECG returns to normal. Patients with chorea may need wheelchair assistance and homebound instruction until movements improve.

  • Medications for Heart Failure:

    • ACE Inhibitors (Captopril, Enalapril):

    • Beta Blockers (Bisoprolol, Metoprolol):

    • Diuretics:

    • Digitalis (Digoxin):

3. Enhancing Patient Comfort

  • Salicylates (Aspirin): For arthritis-related discomfort.

  • Bed Rest: To reduce joint stress and promote healing.

  • Warm Compresses: Applied to painful joints for soothing relief.

  • Bed Cradle: To keep bed linens off affected joints, reducing pressure and pain.

Complications of Rheumatic Heart Disease

  • Heart Failure: Resulting from narrowed or leaky heart valves.

  • Bacterial Endocarditis: Infection of the heart’s inner lining, more likely if heart valves are damaged.

  • Ruptured Heart Valves: A critical emergency requiring immediate surgical valve repair or replacement.

  • Cerebral Stroke: Occurs if a piece of vegetation (infected material) from the heart breaks off and travels to the brain.

  • Pulmonary Hypertension: High blood pressure in the lungs, often due to blood congestion.

  • Atrial Fibrillation: Irregular and rapid heart rhythm originating in the atria.

  • Infective Endocarditis, Pericarditis, and Myocarditis: Inflammatory and infectious heart conditions.

Nursing Diagnoses

  • Decreased Cardiac Output: Related to narrowed heart valves, evidenced by shortness of breath, fatigue, dizziness.

  • Acute Pain: Related to joint inflammation, as reported by the patient.

  • Hyperthermia: Related to inflammation in joints and heart valves, indicated by elevated body temperature.

  • Activity Intolerance: Related to muscle weakness, requiring prolonged bed rest.

  • Self-Care Deficit: Related to joint pain and movement limitations (polyarthritis) and therapy/bed rest requirements.

  • Impaired Skin Integrity: Related to skin inflammation, evidenced by subcutaneous nodules and rash.

  • Risk for Impaired Gas Exchange: Related to fluid accumulation in the lungs due to heart problems.

  • Risk for Injury: Related to involuntary movements of chorea.

  • Risk for Non-compliance with Prophylactic Drug Therapy: Related to the long-term nature and potential burden of preventive treatment.