Cv 2_ Jackson_Viral Myocarditis & Chagas Disease

Front 1

What is the frequent cardiac presentation of myocarditis?

Back 1

cardiac presentation is
frequently one of acute heart failure

Front 2

What is the most common cause of myocarditis? Is it a Bacterial or Viral infection?

Back 2

Viral infections

Front 3

Which viruses account for most cases of myocarditis?

Back 3

Enteroviruses
(Coxsackie A&B)

Front 4

What are the most common causes of NEONATAL MYOCARDITIS?

Back 4

Coxsackie B and Adenovirus

Front 5

What is the most common cause of ADULT MYOCARDITIS?

Back 5

Coxsackie B

Front 6

What are the most common causes of myocarditis in IMMUNOCOMPROMISED pt's?

Back 6

CMV, HIV, Parvo Virus B19 and HHV6

Front 7

There are some NON-VIRAL causes of myocarditis such as BACTERIA. What inflammatory mediators do they release?

Back 7

TLR2 & TLR4

Front 8

What are the non-infectious causes of myocarditis?

Back 8

hypersensitivity rxns

systemic immune diseases like rheumatoid dz, SLE or polymyositis

Front 9

What do we see microscopically with myocarditis?

Back 9

PMN Infiltration

Myocyte damage

Front 10

How do most neonates catch myocarditis?

Back 10

60-70% acquired from mother

ADENOVIRUS

50-75% mortality rate within 1st week

Front 11

Who is more likely to get myocarditis? Males or Females

Back 11

Male incidence is 2x that of females

Front 12

Myocarditis in adults is likely preceded by what symptoms?

Back 12

Cold
Flu-like
GI--> enterovirus

Front 13

What are some possible outcomes of myocarditis in adults?

Back 13

1) Asymptomatic

2) Transient Inflammation, full recovery

3) Becomes Chronic

4) Continuing damage mediated by antibodies, macrophages and Cytotoxic T lymphocytes

Front 14

you're looking at a slide and you see trypanosomes and PMN infiltrate. What's your dx?

Back 14

Chagas dz

Front 15

What happens when a patient survives an acute phase of myocarditis?

Back 15

Inflammatory lesions either resolve or heal by progressive fibrosis (remodeling)

Front 16

During the viral phase of myocarditis, how does the virus enter the host GI or Respiratory system?

Back 16

Coxsackie-adenoviral receptor
(CAR)

CAR is highly expressed in the heart, brain and gut

HIGH # of CARs in Neonates

Front 17

What are the 3 phases of myocarditis?

Back 17

Viral Phase --> Virus enters via CAR

Immune Response--> acute myocardial injury and release of intracellular antigen (Cardiac Myosin)

Cardiac Remodeling--> fibrosis--> HF, MI, Death

Front 18

Explain the autoimmune component of myocarditis

Back 18

Autoimmune mechanisms caused by viral release of cardiac myosin

T cells and antibodies can react with viral proteins that
mimic those of the host (ex. cardiac myosin) - this is termed
molecular mimicry and it triggers autoimmunity

Front 19

What innate immune cells are activated during viral infection causing myocarditis?

Back 19

Macrophages and NK cells

Front 20

What cells have a role in the adaptive immune response during a viral infxn causing myocarditis?

Back 20

Helper T cells, Effector T cells
B cells (antibodies)

Front 21

During myocarditis, viruses activate the innate immune sytem stimulating the relase of what?

Back 21

type I interferons (IFN-a and -B)

Front 22

Activation of innate immunity leads to?

Back 22

Acquired Immunity

Front 23

Adult myocarditis tx?

Back 23

Supportive care, bed rest, cardiac monitoring, anti-arrhythmics

Usually resolves w/o complication

Front 24

What is the gold standard for dx'ing myocarditis?

Back 24

Biopsy

Looking for presence if inflammatory cells with evidence of myocyte degeneration

Front 25

Neonatal myocarditis tx?

Back 25

supportive care, fluid management, digoxin and diuretics, ACE I's

Front 26

What are some newer diagnostic tools for dx'ing myocarditis?

Back 26

PCR and in situ hybridization
(molecular tools to detect virus and viral nucleic acid);


PET-CT (detects inflammation of the myocardium)

Cardiac magnetic
resonance imaging allows visualization of the entire
myocardium

EKG, Troponin and Creatine Kinase release

Front 27

What do patchy white areas in a CMR indicate?

Back 27

Inflammation -->myocarditic lesions

Front 28

Headache, fever, malaise, weight loss

Romaňa’s sign (eye swollen shut)

Time in South America

Back 28

Acute Chagas Disease

Front 29

What is the infectious agent of Chagas disease?

Back 29

Trypanosoma cruzi

Front 30

Patient presents with signs/symptoms of arrhythmia or cardiac failure
along with chagoma, Romaña’s sign, with history of
presence in South or Central America

Back 30

Acute Chagas Disease

Front 31

Patient presents with signs/symptoms of arrhythmia or cardiac failure, along with signs of megaesophagus (dysphagia,odynophagia, ptyalism), or megacolon (severe constipation, abdominal pain) with history of presence in South or Central America

Back 31

Chronic Chagas Disease

Front 32

What is the most common vector of Chagas disease?

Back 32

Triatomid insect =reduviid = “Kissing bug”

They bite you then shit in the bite, thus, transferring the parasite

Front 33

What is the kissing bug's habitat?

Back 33

Rural areas in mud, or adobe homes

South America

Front 34

Explain Acute phase Chagas Disease

Back 34

Acute Phase (1 – 2 weeks)

* Usually mild; weeks to months

* Fever, fatigue, rash

* Swelling at infection site;
Chagoma

* Rarely, myocarditis

Front 35

Explain Chronic Chagas Disease

Back 35

Chronic Phase (10 – 30 years)

*Palpitations, dyspnea, syncope
due to enlarged heart, altered heart
rate or rhythm (may be fatal)

*Dysphagia or constipation → due
to mega-esophagus, mega-colon