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Infectious Diseases of the Heart

Oct 03, 20247 min read

Pericarditis

Inflammation of the pericardium, the thin outer covering of the heart.

  • Associated with malignant neoplasms, idiopathic causes, infective organisms, as a post-MI syndrome (Dressler’s Syndrome), postpericardiotomy syndrome, systemic connective tissue disease, and chronic renal failure (due to metabolites), chest trauma
  • “Short-course” Pericarditis: <6 months; longer is considered Chronic Pericarditis.
  • Chronic Constrictive Pericarditis leads to thickening of the pericardium by fibrous tissue formation, which leads to rigidity and subsequently inadequate ventricular filling, which results in heart failure.
graph LR
A(Chronic Pericarditis)-->B(Pericardial Rigidity)
B-->C(Inadequate Ventricular Filling)
C-->D(Heart Failure)

Assessment

  1. Pain radiating to the neck, shoulder and back aggravated by inspiration, coughing and swallowing, and is worst when supine (inversely, relieved by sitting up or leaning forward)
  2. Pericardial Friction Rub: a scratchy, high-pitched sound produced by the visceral and parietal pericardium rubbing together.
  3. Signs of RSHF when pericardial rigidity develops.
  4. Thickening of the Pericardium as revealed by CXR or ECHO.
  5. Increased WBC count
  6. Atrial Fibrillation is also common

Intervention

  • NSAIDs (inhibition of prostaglandin, which causes pain) for pain management
  • Corticosteroids if caused by an autoimmune disease.
  • Antibiotics if caused by m.o.
  • Pericardial Drainage (Pericardiocentesis, Pericardiostomy), the removed fluid may also be used for cultures and other studies.
  • Radiation or Chemotherapy if caused by malignancy.
  • Hemodialysis if caused by uremic pericarditis secondary to renal failure.
  • Positioning for comfort.
  • Pericardiectomy for those with chronic constrictive pericarditis.
  • Monitor for Pericardial Effusion (>50mL)

Pericardial Effusion

The accumulation of fluid in the pericardial cavity, which may eventually result in cardiac tamponade.

Manifestations

  • Jugular Distention: increased CVP
  • Pulsus Paradoxus: hypotension with a further decrease of BP during inspiration.
  • Distant/Muffled Heart Sounds
  • Circulatory Collapse as a result of decreased cardiac output.
  • Altered Perfusion (brain: lethargy, stuporous; systematic: cool, clammy skin; kidneys: oliguria)

Intervention

  • Emergency Care: Pericardiocentesis
  • Nursing Responsibilities:
    • Preparation of items such as PPE, skin prep., sterile field, etc.
    • The patient is positioned in a semi/high-fowlers to allow gravity to help drain pericardial effusion.

Myocarditis

Inflammation of the muscular layer of the heart. Abnormal function resulting from inflammation reduces CO and predisposes the client to CHF. Ischemia of the myocardium results in tachycardia and dysrhythmias.

  • Viral, bacterial, fungal, and parasitic infection.
  • Chronic alcohol and cocaine abuse
  • Secondary to Radiation Therapy
  • Autoimmune Disorders
  • Bulimic patients abusing Ipecac Syrup to induce vomiting, causing myocardial damage.
  • May be idiopathic.
  • Its complication is cardiomyopathy, where myocardial dilation and hypertrophy occurs, which ends up in decompensation.

Assessment

  • Pain, Fever, Tachycardia, Dysrhythmias, Dyspnea, Malaise, Fatigue, Anorexia, Pallor/Cyanosis, RSHF Symptoms
  • Increased WBC, Elevated CRP, Elevated Cardiac Enzymes, Abnormal ECG
  • CXR and ECHO reveals cardiomegaly
  • Most definitive: endomyocardial biopsy for testing

Intervention

  • Treatment of underlying cause (antibiotics if m.o.)
  • Bed rest, Na+ restriction, Cardiotonic Drugs (Digitalis)
  • Monitor:
    • Cardiopulmonary status and complications (CHF, Dysrhythmias)
    • Vital Signs, Daily Weight, I&O
    • Heart and Lung Sounds
    • Pulse Oximetry
    • Cardiac Monitoring
    • Dependent Edema

Rheumatic Fever

Inflammation that follows an URTI (tonsillitis, pharyngitis, laryngitis) caused by GABHS. When the heart becomes affected, it becomes “Rheumatic Carditis/Endocarditis”.

  • Antibodies are formed to destroy GABHS, which cross-react to proteins found in the connective tissues of the heart, joints, skin, and nervous system.
  • This may result in Pancarditis, inflammation of all layers of the heart including valvulitis.
  • WBCs migrate to the endocardium where the inflammation is, which end up accumulating inflammatory debris (dead cells from phagocytosis) called “vegetations” around the valve leaflets, which can cause obstruction in blood flow (circulatory stasis).
  • The vegetations or thrombi formed from obstruction may embolize and settle in any part of the body.
  • Atrial fibrillation may result from the vegetations.

Assessment

Major/Classic Symptoms

(Separate manifestations of the autoimmune reaction towards the heart, joints, nervous system, and skin)

  • Carditis: characterized by the formation of Aschoff’s Bodies, Murmurs, and a Pericardial Friction Rub, which may result in CHF.
  • Polyarthritis: swelling of multiple joints that is warm, red, and painful.
  • Chorea (Sydenham’s Chorea, St. Vitu’s Dance): involuntary grimacing and inability to use skeletal muscles in a coordinated manner (involvement of the CNS)
  • Subcutaneous Nodules: marble-sized nodules around the joints.
  • Erythema Marginatum: quickly-disappearing red spotty rashes that leave irregular circles on the skin.

Minor Symptoms

  • Reliable history of RF or evidence of pre-existing RHF.
  • Arthralgia without inflammation, pain, or limited movement
  • Fever: 38.9 - 40C
  • Increased ESR, ASO Filter and CRP
  • ECG: Prolonged PR Interval

Diagnosis

Clinical diagnosis of Rheumatic Carditis is done with the Jone’s Criteria: assessment of 2 Major, or 1 Major + 2 Minor Symptoms + Supporting evidence of recent streptococcal infection

Intervention

The best intervention is prevention; prevention of early identification of a streptococcal infection and prophylaxis with proper antibiotics. The nurse should be familiar with the S/S of streptococcal pharyngitis.

Streptococcal Pharyngitis

  • Fever (38.9 - 40C)
  • Chills
  • Sore Throat
  • Diffuse redness of throat with exudates on the oropharynx.
  • Enlarged/tender lymph nodes (Cervical Lymphadenopathy)
  • Abdominal Pain
  • Acute Sinusitis and Acute Otitis Media

Management

  • Antibiotics, the drug of choice of which is penicillin.
  • Aspirin as an anticoagulant
  • Steroids as an antiinflammatory
  • Antipyretics and Hydration for fevers
  • Antibiotic Prophylaxis with a monthly injection of penicillin
  • Bed Rest with diversionary low-effort activities
  • Assess for progression or improvement of heart involvement

Heart Failure

Heart failure is the loss of pumping ability of the heart. It may be categorized as Left-Sided or Right-Sided Heart Failure (LSHF, RSHF). There are many causes, but in terms of physiological changes:

  • Preload is greatly reduced (e.g. hypovolemia)
  • Preload is greatly increased (e.g. hypervolemia, pancytopenia)
  • Afterload is obstructed or difficult (e.g. valvular stenosis/regurgitation, hypertension)
  • Damage to the heart muscle (e.g. cardiomyopathy, M.I.)
  • Increased metabolic states (e.g. Hyperthyroidism, Graves Disease, Pheochromocytoma)

Compensatory Mechanisms of the Heart

Once the heart reaches its physical limit, cardiac decompensation occurs.

  1. Ventricular Dilatation
  2. Ventricular Hypertrophy
  3. Sympathetic Nervous System Stimulation → Tachycardia

Manifestations

Left-Sided Heart Failure

LSHF will always be followed by RSHF if left untreated.

  • Forward Effect: Decreased Systemic Perfusion (Cerebral, Renal, Body Cells)
  • Backward Effect: Pulmonary Congestion and Edema

Right-Sided Heart Failure

  • Backward Effect: Systemic Congestion (Distended Jugular Veins, Increased CVP, Hepatosplenomegaly) and Edema (Dependent Edema, Ascites, Generalized Edema), Increased SGPT & SGOT (Impaired Liver Function), Anorexia and G.I. Distress

Assessment

  • Heart/Lung Sounds: “galloping horse”, crackles/rales (blowing into a can of soda with a straw).
  • The patient feels like they are drowning.

Diagnostic Findings

  • CXR: Cardiomegaly
  • Pleural Effusion
  • ECG: ventricular hypertrophy, dysrhythmias
  • ECHO: reveals cardiac valvular changes, pericardial effusions, chamber enlargement, and ventricular hypertrophy.

Management (Medical)

  1. Low Na+ Diet and Fluid Restrictions
  2. Inotropic Agents: Increased contractility, slows heart rate and conduction.
    • Digoxin (Lanoxin): the mainstay treatment for HF.
      • Also decreases sympathetic activity and increases parasympathetic activity.
      • Always check for digitalis toxicity (0.5 to 2 ng/mL), the main presenting symptom of which is bradycardia, along with anorexia, N&V, rapid, slow, irregular heart rate, and disturbance in color vision.
      • Antidote: Digibind
      • Do not administer if assessment is found to be <60 BPM and supplement potassium if patient is hypokalemic.
    • Dopamine (Intropin), Dobutamine (Dobutrex)
  3. Diuretics: Furosemide (Lasix), Chlorothiazide (Diuril)
    • Inhibition loss of sodium means potassium is exchanged and excreted in turn. A serum test is done prior to usage of Furosemide, and supplementation is ordered if hypokalemic. Hypokalemia also contributes to digitalis toxicity due to its direct effect on cardiac contraction.
  4. Vasodilators: Nitroglycerin
  5. ACE Inhibitors: “-prils”

Nursing Management

Most clients manage chronic heart failure at home.

  • Administer prescriptions and evaluate effect.
  • Promote positive cardiac output.
  • Monitor for excess fluid volume (weight gain) and electrolyte imbalances (potassium)
  • Promote oxygenation and balance activity according to tolerance.

Pulmonary Edema

The accumulation of fluid in the lungs. This may be caused by LSHF, but may also be caused by non-cardiogenic conditions:

  • Pulmonary Embolism
  • Infection
  • Alteration of Pulmonary Capillary Membrane

Assessment

  • Dyspnea, Orthopnea
  • Wheezing
  • Restlessness
  • Productive cough with pink frothy sputum
  • Cyanosis
  • Tachycardia
  • Apprehension
  • ABG: Metabolic and Respiratory Acidosis, Severe Hypoxemia (<50mmHg PaO2, >50mmHg PaCO2)

Management (Medical)

  • Drug Therapy
    • Inotropics: Dopamine (Intropin), Dobutamine (Dobutrex), Amrinone (Inocor), Digitalis
    • Diuretics
    • Vasodilators e.g. nitrates, ACE Inhibitors, Ca++-channel blocker
    • Morphine for anxiety, apprehension
  • Oxygen Therapy
  • If ineffective, invasive measures are used.

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