Infections of the Heart Flashcards
1
Q
Infections of the Heart
- Endocarditis
- Myocarditis
- Pericarditis
A
- Endocarditis
- Inflammation of the heart lining, or endocardium
- Typically involves the valves
- Myocarditis
- Inflammation of the heart muscle
- Pericarditis
- Inflammation of the outside of the heart & sac
2
Q
Bacterial (Infective) Endocarditis
- General
- Most common cause of infective endocarditis
- Acute
- Subacute
- Histology
- Major complications
A
- General
- Bacteria (or fungus) infects valve surfaces
- Damages & destroys valves
- Abnormal valve can act as nidus of infection
- i.e. Stenotic, insufficient, bicuspid, prosthetic
- Mitral & aortic most common
- Tricuspid valve in IV drug abuse
- Most common cause of infective endocarditis
- Staphylococcus aureus
- Acute
- Normal valve
- Highly virulent organism
- Rapid course w/ high mortality
- Subacute
- Abnormal valve
- Less virulent organism
- Protracted course (weeks to months)
- Histology
- Acute inflammation
- Inflammatory debris
- Bacterial colonies
- Staphylococcus epidermitis
- Staphylococcus aureus
- Pseudomonas aeruginosa
- Major complications
- Destruction / rupture of valve
- Heart failure
- Valve insufficiency
- Septic embolic events
- Subacute: valve fibrosis & stenosis
3
Q
Bacterial (Infective) Endocarditis Classic Lesions
A
- Septic emboli to other organs & tissues
-
Splinter hemorrhages
- Subungual vascular lesion
-
Osler nodes
- Painful red-purple nodules on fingers or toes
- Occur around glomus body
-
Janeway lesions
- Non-painful hemorrhagic lesions on palms & soles of feet
-
Roth spots
- Retinal hemorrhages
- Kidney abscesses
- Brain infarcts
4
Q
Rheumatic Heart Disease
- Endocarditis
- Myocarditis
- Pericarditis
- Pancarditis
A
- Endocarditis
- Vegetations on heart valve surfaces
- Myocarditis
- Inflammation of the myocardium (heart muscle cells)
- Rare: <1% of patients get fulminant rheumatic fever w/ myocarditis
-
Achoff body: diagnostic myocardial lesion
- Composed of t-cells, plasma cells, & activated macrophages
-
Anitschow cells: diagnostic cells
- Activated, multinucleated macrophages w/ slender wave chromatin “caterpillar cells”
- If someone dies from rheumatic fever, they typically have myocarditis
- Pericarditis
- Inflammation of the pericardium
- Pancarditis
- Involvement of epicardium, myocardium, & pericardium
5
Q
Viral Myocarditis
- Myocarditis
- Due to…
- Caused by…
- Clinical features
A
- Myocarditis
- Inflammation of the myocardium
-
Almost exclusively due to infection
- Viral: Coxsackie virus, Influenza virus
- Chagas disease, Lyme diesease
- Caused by…
- Rheumatic heart disease (can cause death)
- Immune reactions (lupus, rheumatic fever)
- Transplant rejection
- Drug reaction (eosinophilic)
- Clinical features
- Viral illness symptoms
- Cardiac arrhythmia, palpitations
- Dyspnea
- Pre-cordial discomfort
- Can progress rapidly to heart failure & death
6
Q
Viral Myocarditis
- Gross pathology
- Microscopic pathology
- Clinical pathology
- Course & complications
A
- Gross pathology
- Pale, floppy myocardium
- Microscopic pathology
- Lymphocytic (or mixed) infiltrate
- Myocyte necrosis
- Clinical pathology
- Elevated CK-MB & troponins
- Course & complications
- No sequelae
- Symptoms w/ recovery
- Chronic heart disease
- Dilated cardiomyopathy
- Death
7
Q
Why do you see elevated cardiac enzymes in myocarditis?
A
Inflammatory cell death
8
Q
Eosinophilic Myocarditis
- Drug reaction
- Chagas disease
A
- Drug reaction (hypersensitivity)
- Antibiotics, chemotherapeutics
- Typically have a rash or other immune response
- Chagas disease (protozoal infection)
- Trypanosoma cruzi: American trypanosomiasis
- “Kissing bug”
- Most patients get caridac involvement
- Can lead to immune-mediated myocarditis (Achalasia in GI path)
9
Q
Giant Cell Myocarditis
A
- Unusual varient of “garden variety” myocarditis
- Mixed infiltrate w/ giant cells
- More extensive myocyte necrosis
- Aggressive course w/ poor prognosis
10
Q
Myocarditis Summary
- Lymphocytic
- Eosinophilic
- Giant cell
- Requirements for pathology diagnosis
A
- Lymphocytic
- Viral, immune reactions
- Eosinophilic
- Hypersensitivity
- Giant cell
- Unique aggressive form
-
Requirements for pathology diagnosis
- Inflammatoyr infiltrate
- Myocyte damage &/or necrosis
11
Q
Pericarditis
- General
- Clinical findings
- Different types
A
- General
- Inflammation or infection of the epicardium &/or pericardium
- Caused by a variety of conditions
- Primary pericarditis is viral
- Typically see accompanying fluid collection
- Clinical findings
- Chest pain
- Sharp, retrosternal, radiates to back
- Relieved by sitting up or leaning forward
- Worsened w/ lying down
- Friction rub on auscultation
-
Caridac tamponade
- Life-threatening event
- Fluid fills heart sac (usually >150 ml)
- Beck’s triad: jugular venous distention, hypotension, muffled heart sounds
- Emergent treatment: pericardiocentesis
- Chest pain
- Different types
- Serous
- Fibrinous
- Purulent (suppurative)
- Hemorrhagic
12
Q
Serous Pericarditis
- General
- Caused by…
A
- Straw-colored pericardial effusion
- Protein rich exudate
- Caused by
- SLE (lupus)
- Rheumatic fever
- Viral infection
13
Q
Fibrinous Pericarditis
- General
- Caused by…
A
- General
- “Sticky” adherent fibrin strands on surface
- Fibrin rich exudate
- Caused by…
- Post-pericardotomy syndrome after coronary artery bypass graft surgery
- Acute myocardial infarction
- Dressler’s syndrome
- Uremia (uremic pericarditis): renal failure
14
Q
Purulent (Suppurative) Pericarditis
- General
- Caused by…
A
- General
- Thick yellow effusion (pus)
- Inflammatory exudate
- Caused by…
- Infection
15
Q
Hemorrhagic Pericarditis
- General
- Caused by…
A
- General
- Bloody inflammatory effusion
- Caused by…
- Tumor invasion of pericardium
- Tuberculosis (chronic)
- Bacterial infection
16
Q
Pericarditis
- Acute complications
- Chronic complications
A
- Acute complications
- Cardiac tamponade
- Cardiac arrhythmia
- Chronic complications
- Constrictive (restrictive) pericarditis
- Scarring w/ adhesions
