Endocarditis, Myocarditis / Cardiac Patho / Test 2/2 Flashcards
Infective endocarditis is caused by ?
Microbial infection of the lining of the heart.
Characteristic lesions of Infective endocarditis?
Vegetation (valves)
Carditis that Evolves over weeks or months ?
(SBE) Sub acute Bacterial Endocaditis
Carditis that has a rapid onset of days to weeks ?
(ABE) Acute Bacterial Endocarditis
Susceptible hosts for Infective Endocarditis ?
Elderly Children with CHD repairs Mitral Prolapse IV drug abuse Patients undergoing CPB Nosocomial
Nosocomial
(Hospital Aquired Infection)
Infective Endocarditis Etiologic organisms ?
Streptococci
Staphylococci
With Non-Infective Endocarditis what can occur following some form of endothelial damage?
Platelet deposition on valves
What can develop on valve in a variety of clinical conditions, specifically non-infective endocarditis.
Sterile thrombotic lesions
Myocarditis is an inflammatory disease of cardiac muscle
It can be:
& May be:
Acute
Sub-acute
Chronic
Focal or diffuse
Myocarditis may be caused by infectious organisms, such as viruses, bacteria, fungi, protozoa, or helminths, or by a toxin, such as cocaine
Myocarditis can also be associated with systemic illnesses such as?
- collagen-vascular,
- autoimmune diseases, &
- granulomatous,
Non-Infectious causes for Myocarditis ?
Cardiotoxins
Hypersensitivity Reactions
Systemic Disorders
The true incidence of myocarditis is unknown because the majority of cases are asymptomatic.
Involvement of the myocardium has been reported in
__ to __ percent of patients with acute viral infections
Autopsy studies have revealed varying estimates of the incidence of myocarditis. A five percent prevalence of active myocarditis was reported in a high-risk group of 186 sudden, unexpected medical deaths in children
1 to 5%
Certain groups appear to be at increased risk of virus-induced myocarditis, and the course may be hyperacute. Name 4 groups at risk?
Young Males
Pregnant women
Children (particularly neonates)
Immunocompromised patients
What contributes to myocyte damage and necrosis?
- Direct viral-induced myocyte damage and
- Post-viral immune inflammatory reactions
Inflammatory lesions and the necrotic process may persist for months, although the viruses only replicate in the heart for at most ?
2 -3 weeks after infection
Evidence from experimental models has incriminated what contibuting factors to Myocarditis ?
cytokines such as:
- interleukin-1 and TNF,
- oxygen free radicals and
- microvascular changes
The clinical presentation of myocarditis is variable
Most cases are ?
Sub-clinical
disease that is not severe enough to present definite or readily observable symptoms.
Myocarditis may be the cause of unexpected sudden death, presumably due to what?
Ventricular tachycardia or Ventricular fibrillation
Most common infectious etiologic agents “VIRAL” causes of Myocarditis in the USA?
- Influenza A & B
- Enteroviruses (most common)
- CMV
- HIV
Most common infectious etiologic agents “PARASITIC” causes of Myocarditis?
- Chagas’ disease
- toxoplasmosis
- trichinosis
Chagas’ disease AKA
(Trypanosoma cruzi) (most common cause of myocardits in/from S. America)
Most common infectious etiologic agents “BACTERIAL” causes of Myocarditis?
- Lyme disease
- Diphtheria
How do you get Diphteria?
(injury from toxins of Corynebacterium diphtheriae)
Describe the morphology of Myocarditis ?
- Cardiac Dilation
- Flabby myocardium
- Pale
- Focal Petechial Hemorrhages on the visceral pericardium.
How would you identify
“ACUTE VIRAL” Myocarditis under the microscope ?
- Edema
- Inflammatory infiltrate of lymphocytes.
- Myocyte degeneration and/or necrosis
How would you identify “CHRONIC VIRAL” Myocarditis under the microscope ?
-Inflammation is less
conspicuous
-Myocardial fibrosis
How would you identify “PARACITIC” Myocarditis under the microscope ?
Identify the organisms
How would you identify “BACTERIAL” Myocarditis under the microscope ?
neutrophilic inflammatory infiltrate
toxoplasmosis
Parasitic disease
How would you identify Cardiac Transplant Rejection under the microscope ?
- interstitial lymphocytes
- myocyte degeneration
- may resemble viral type
How would you identify “GIANT CELL Myocarditis” under the microscope ?
- multinucleated giant cells present
- lymphocytes, macrophages, eosinophils
- foci of necrosis
3 Myocarditis Clinical Features
?
- Asymptomatic
- Congestive Failure
- Arrhythmias
6 Cardiotoxins to blame for myocarditis?
- Catecholamines
- Anthracyclines
- Cocaine
- Alcohol
- Carbon monoxide poisoning
- Chemo Drugs (Doxorubicin)
Most popular Virus to blame for myocarditis?
Coxsackie Virus
Lyme disease can cause myocarditsis, what is the name of the organism responsible ?
Borrelia Burgdorferi
Chagas’ Disease is a Protozoal infection that originated from South America. What is the name of the organism responsible fo this disease?
American trypanosomiasis
6 Systemic disorders that can cause myocarditis?
- Collagen-Vascular diseases
- Sarcoidosis: Granulation tissue
- Kawasaki Disease
- Hypereasinophelia
- LUPUS
- Scleroderma: Excess collagen
Name the layers of the heart in order, starting from inside the heart?
EM VP PC PP FP
Endocardium Myocardium Visceral Pericardium Pericardial Cavity Parietal Pericardium
