Lecture Notes: Infectious Inflammatory Diseases of the Heart

Overview

Infectious inflammatory diseases of the heart include conditions such as pericarditis, endocarditis, and related complications.

Definition: Inflammation of the pericardium, including the epicardium.
Pericardium: Holds the heart in place; contains serous fluid for cushioning.
Etiologies:
- Viral infections
- Tuberculosis (TB)
- Rheumatological disorders
- Uremia
- Idiopathic causes
- Cancer of nearby structures
Manifestations:
- Pleuritic chest pain (worse with inspiration, improves when leaning forward)
- Pericardial friction rub (scratchy sound at left sternal border)
- EKG changes: nonspecific ST elevation, PR segment depression
Treatment:
- Colchicine and NSAIDs (best combined)
- Prednisone as an alternative

Serous Pericarditis: Viral origin, serous effusion without bacteria.
Fibrinous Pericarditis: Fibrinous exudate post-MI or trauma (Dressler syndrome); colchicine may be given post-surgery.
Purulent Pericarditis: Bacterial in nature, requires antibiotics and drainage.

Pathophysiology: Chronic inflammation leads to scarring and loss of elasticity.
Effects: Diastolic heart failure, pericardial knock sound, JVD, dyspnea, edema.

Normal Fluid Amount: 15-50 mL in pericardial cavity.
Causes: Hemorrhagic (surgery, trauma), malignant, exudative (TB, bacteria), transudative (CHF, nephrotic syndrome).
Diagnosis: Chest x-ray, echocardiogram, and pericardiocentesis (fluid analysis).

Description: Rapid or large effusion impairing ventricular filling.
Symptoms: Beck's triad (hypotension, JVD, distant heart sounds), exaggerated pulsus paradoxus.
Pathophysiology: Effusion compresses heart, prevents adequate diastolic filling.

Definition: Inflammation of the endocardium, affecting heart valves.
Etiology: Secondary to valve vegetations, injury from turbulent flow.
Acute Infective Endocarditis:
- Causes: Virulent organisms like Staph aureus; often affects normal valves.
- Symptoms: High fevers, positive blood cultures, valve destruction.
Subacute Infective Endocarditis:
- Causes: Less virulent organisms, affects damaged/prosthetic valves.
- Symptoms: Insidious onset, smaller vegetations, harder to culture.
- Physical Findings: Splinter hemorrhages, Janeway lesions, Osler nodes, Roth spots.
Diagnosis: Echocardiogram (transesophageal preferred), blood cultures.
Treatment: 6 weeks of antibiotics, possible surgery if severe.

Characteristics: Platelet-fibrin aggregates, immune complexes without organisms.
Associations: Mitral valve, cancer, hypercoagulable states.
Treatment: Requires anticoagulants if embolization risk.