Inflammatory Heart Disease

Inflammatory Heart Disease Notes

Learning Objectives

• Identify the layers of the heart.

• Understand the different etiologies and risk factors for:

  • Pericarditis

  • Myocarditis

  • Endocarditis

• Differentiate clinical findings in:

  • Pericarditis

  • Myocarditis

  • Endocarditis

• Anticipate diagnostic tests for evaluating inflammatory heart disorders.

• Plan nursing interventions and care for patients with inflammatory heart disease.

• Understand the consequences of untreated inflammatory heart disease.

• Identify patient education points for health promotion related to infectious heart diseases.

Layers of the Heart ( ๑‾̀◡‾́)σ"

• Pericardium (outermost layer of heart):

  • Fibrous pericardium (outermost layer)

  • Serous pericardium (parietal layer)

  • Serous visceral (epicardium, on the heart muscle itself)

• Myocardium (middle): Thick muscle layer with cardiac fibers.

• Endocardium (innermost layer): Inner endothelial lining. Makes up heart chambers and valves themselves.

Acute Pericarditis (๏ᆺ๏υ)

• Definition: Inflammation of the pericardial sac/Inflammation outside the heart.

  • Heart gets compressed and cannot pump. Less cardiac output = less oxygen out.

    

• Etiology:

  • Idiopathic: Unknown cause.

  • Infectious: Viral, bacterial, fungal, parasitic.

  • Noninfectious: Acute myocardial infarction (AMI) (leads to inflammation cascade triggers immune system), renal failure, certain cancers, trauma, radiation, myxedema (severe hypothyroidism/swelling/thickening of skin), dissecting aortic aneurysm.

  • Autoimmune (hypersensitivity type III): Dressler’s syndrome (pericarditis after heart injury with fluid buildup in peri sac), post-pericardiotomy syndrome (surgery complication), rheumatic fever (related to strep throat infection), RA.

  • Think “HAIR”

    • H: Heart attack → noninfectious

    • A: Autoimmune Disorders → RA, SLE (lupus), scleroderma (hardening of skin), Dressler’s syndrome, rheumatic fever.

    • I: Infection → Viral (HIV), bacterial (strep, staph), fungal (candida), parasitic.

    • R: Renal Failure → Uremia (high BUN) → noninfectious

Pathophysiology

• Acute inflammatory response leads to:

  • Influx of neutrophils.

  • Fluid leakage into the pericardial sac.

  • Increased vascularity (vessel size) and fibrin deposition on the epicardium (decreases movement of heart).

• Acute Phase: Occurs within 24-48 hours after MI.

• Subacute Phase: Occurs weeks to months later (e.g., Dressler syndrome).

• Chronic Phase: Lasts over 6 months; leads to friction and adhesions affecting heart movement.

Clinical Manifestations

• Severe chest pain that worsens with deep inspiration or lying flat, relieved by sitting up and leaning forward (tripod).

• Referred pain to shoulders/back.

• Fever (infectious etiology), tachypnea, dyspnea, anxiety.

• Pericardial friction rub (hallmark finding): Scratchy, grating, high pitched sound heard best at the left lower sternal border.

  • Request pt hold their breath and listen to determine if pleural friction or pericarditis because heart will still beat.

Diagnostic Testing

• ECG: Global ST segment elevation.

• Echocardiogram: To assess effusion or tamponade.

• Imaging: CXR, CT or MRI for visualization of the pericardial sac.

• Lab Work: CBC (RBC, WBC), CRP (Inflammatory markers → CRP normal <1), Sed Rate, Troponin (released with cardiac cell death).

• Pericardiocentesis: Fluid analysis (diagnostic and treatment).

Complications

• Pericardial Effusion: Excess fluid leading to muffled heart sounds, potentially compressing the heart.

  • Hiccups → phrenic nerve compression

  • Hoarseness from laryngeal nerve compression

  • Lungs - cough, SOB, increased RR

• *Cardiac Tamponade: Reduced diastolic filling & cardiac output and pulsus paradoxus (SBP decreases w/inspiration), requiring urgent pericardiocentesis. Happens when there is a 1000ml in peri sac. MEDICAL EMERGENCY.

  • Beck’s Triad: Low blood pressure, muffled heart sounds, JVD.

    

Interprofessional Care

• Medications: Antibiotics (if infectious), NSAIDs (unless related to MI), corticosteroids (decrease inflammation → long-term use decreases immune function), colchicine (helps inhibit neutrophils→ decreases inflammation and fluid).

• Supportive: Oxygen, bed rest (perform turns, ROM, nutritious meals), positioning (tripod).

• Uremic Pericarditis: Needs dialysis (renal failure).

• Surgical Interventions:

  • Pericardiocentesis → fluid drainage

  • Pericardial “window.” → remove portion of pericardial sac and fluid spills into pleural cavity → reabsorbs into body

    • Indications: Cardiac tamponade, purulent pericarditis drainage, malignancy.

    • Potential Complications:

      • Dysrhythmias from sudden drainage

      • Pneumothorax

Chronic Constrictive Pericarditis

• Definition: Fibrosis (thick) and rigidity of the pericardium, leading to decreased elasticity, restrictive ventricular filling (diastole) → reduced cardiac output.

• Etiology: Tuberculosis, heart surgery, radiation therapy, idiopathic.

• Clinical Manifestations: Symptoms resemble right-sided heart failure and Cor Pulmonale (dyspnea on exertion, edema, ascites, JVD), fatigue.

• Treatment: Pericardiectomy (remove pericarditis) and diuretics (decreases preload/diastolic filling)

Acute Myocarditis (ᗒᗣᗕ)՞

• Definition: Inflammation of the myocardium (thick muscle layer with nerves).

  • Contains all cardiac fibers and nerves like bundle of His and Purkinjie fibers.

• Etiology: Infectious (viral, bacterial, fungal), noninfectious (radiation, drugs), or idiopathic.

  • Generally related to bacterial etiology.

Pathophysiology of Myocarditis

• Causative agents invade and damage myocytes -> trigger an immune response → cytokines release → autoimmune inflammation (body attacks self) → necrosis.

Clinical Manifestations of Myocarditis

• Early symptoms: Fever, fatigue, myalgia/muscle aches, pharyngitis (especially if damage to nerves), lymphadenopathy (enlarged lymph nodes).

• Cardiac signs (if present) can appear 7-10 days after infection

  • Leads to pericarditis → pleuritic chest pain (increases with inspiration), pericardial rub.

  • Pericardial effusion.

• Late signs may include heart failure symptoms: S3, crackles/rhonchi, peripheral edema, JVD.

Diagnostic Testing for Myocarditis

• ECG: ST segment changes, dysrhythmias, conduction abnormalities (inflammation of myocardium fibers and nerves).

• Echocardiogram: Assess effusion or tamponade.

• Lab tests: CBC, troponin (will be elevated similar to a heart attack due to necrosis from autoimmune reaction to myocytes), and viral titers.

• Endomyocardial Biopsy

Complications of Myocarditis

• Decreased cardiac output; severe heart failure (related to dilated cardiomyopathy) or sudden cardiac death (dysrhythmias related to conduction abnormalities, HF → EJ will drop due to dilated CMP).

• Severe HF management may require advanced support such as intra-aortic balloon pumps or heart transplant.

• Medications: Ace, beta, diuretics to manage HF s/s

  • digoxin, anticoagulants, causative treatment aka antivirals or immunosuppressive)

Infective Endocarditis (IE) =＾● ⋏ ●＾=

• Definition: Infection of the endocardium affecting cardiac valves.

• Etiology: Bacterial, viral, or fungal.

• Two Main Classifications: Acute (rapid manifestations of valvular dysfunction) of subacute (preexisting valve disease with clinical course → stenosis)

Risk Factors for Endocarditis

• Previous instances of IE, IV drug abuse, age-related changes, prosthetic valves, invasive procedures (pacemaker, dialysis, central lines, surgery), dental surgery.

Pathophysiology of Endocarditis

• Three Stages:

  • Bacteremia (bacterial invasion)

  • Adhesion: Damage to endothelium supports the attachment of infective organisms.

  • Vegetation: Fibrin, leukocytes, platelets, and microbes stick to the valve or endocardium.

    • Left-sided can move to brain (altered LOC), kidneys (oliguria or anguiria), spleen (left upper quadrant pain and immune function decreases), extremities (pallor).

    • Right-sided can cause a PE

Clinical Manifestations of Endocarditis

• Nonspecific symptoms (acute → weakness, malaise, fatigue) and signs involving multiple organ systems. Subacute involves back pain, abdominal discomfort, anorexia. Vascular manifestations include splinter hemorrhages, petechiae. New or changing systolic murmur.

Diagnostic Testing in Endocarditis

• Blood cultures twice from different sites, ESR, CRP, echocardiography (US of heart), and Duke criteria to establish diagnosis (major = pos blood culture, pos IE organism, new vegetation).

• Health history, recent dental surgery, ask if they’ve had infective endocarditis

Complications of Endocarditis

• Systemic embolization of vegetations, heart valve damage, myocardial invasion leading to heart failure, and potential for sepsis.

• Non-specific: Fever, malaise, fatigue.

Interprofessional Care for Endocarditis

• Prophylaxis with antibiotics for susceptible patients, tailored based on blood culture results. Long-term IV antibiotics may be necessary. Follow-up diagnostics and supportive care are crucial.

• Supportive Care: Treating signs and symptoms (ex. Fever → give antipyretics, hypotensive → fluids (unless HF symptoms), rest)

• Valve Replacement: The bacterium must go away first.

• Trend ESR and CRP

Rheumatic Heart Disease ᕙ(⇀‸↼‶)ᕗ

• Subtype of Endocarditis

• Rheumatic fever can affect all heart layers

• Delayed complication following a stream throat infection → rheumatic fever → rheumatic heart disease.

  • Body develops autoimmune response to strep bacteria

• Education: Don’t share utensils, take full course of antibiotic

  • Early recognition: Get treated if sore throat and witness white patches on throat

Clinical Manifestations of Rheumatic Heart Disease

• Features include arthritis, carditis/pancarditis (heart murmur, HF, pericarditis), and other systemic symptoms such as erythema and involuntary movement.

Diagnostic Studies for Rheumatic Heart Disease

• Physical examination, lab work, echocardiogram for valvular dysfunction, and ECG.

• Nursing Care: Includes administration of prophylactic antibiotics for those with prior RF (q3-4 weeks IM injection until symptoms subside) wand anti-inflammatories to manage symptoms and prevent complications.