Cardiomyopathies, Myocarditis, Pericarditis, Tumors, and Transplant Flashcards
What two general categories of cardiomyopathies are there and how do these differ?
Primary and Secondary
Primary
• Confined to Myocardium - (e.g. myocarditis)
Secondary
• Systemic - (e.g. Hemochromatosis)
What are 3 general types of Cardiomyopathy will you generally see?
Dilated Cardiomyopathy
• ALL CHAMBERS of the heart are HUGE
Hypertrophic Cardiomyopathy
• Ventricular Walls are thickened, possible causing atrial dilation
Restrictive Cardiomyopathy
• Something is causing the heart to be squeezed
Differentiate the typical causes of Dilated, Hypertrophic, and Restrictive Cardiomyopathy.
Dilated
• SYSTOLIC DYSFUNCTION (fucked up contractility)
• ^^Most commonly caused by Chronic Alcoholism
• Dystrophin gene mutations
Hypertrophic
• DIASTOLIC DYSFUNCTION (impaired contractility)
• Idiopathic Hypertrophic Subaortic Stenosis (IHSS)
Restrictive
• Diastolic dysfunction from Infiltration of Material
• common culprits => AMYLOIDOSIS, HEMOCHROMATOSIS, RADIATION INDUCED FIBROSIS
What drug type of myopathy is misfolded dystrophin linked to?
• What drug do we give that can have a similar effect on the heart?
dystrophin - protein mutated in muscular dystrophy (x-linked rec., elarged calves) is part of a complex that links cytoskeleton of muscle fiber to surrounding extracellular matrix
• Doxorubicin - (anthracycline - DNA chelating agent)
Describe the physical appearance of a heart of a person with a Dilated Cardiomyopathy?
• Major risk of these morphologic changes?
- Flabby
- All Chambers Dilated
- Thin Walls - but VARIABLE VENTRICULAR THICKNESS
major risk:
• Mural thrombi and Emboli
• ALSO, see valvular regurgitation due to chamber dilations
What vitamin deficiency commonly seen in alcoholics may commonly lead to Cardiomyopathy?
• TYPE of cardiomyopathy?
• DISEASE MANIFESTATIONS
• Enzyme affected/process affected
BeriBeri caused by a thiamine (vitamin B1) deficiency leads to a DILATED cardiomyopathy i
TWO TYPES:
• wet beriberi - causes heart failure
• dry beriberi- affectsnervous system - leading to psychiatric symptoms
Enzyme:
• Affects Alpha-ketoglutarate dehydrogenase in the CITRIC ACID CYCLE
What are hypertrophic cardiomyopathies often diagnosed?
On autopsy after an athlete drops dead while playing sports (these usually aren’t too symptomatic prior to this)
Hypertrophic Cardiomyopathy
• Part of Heart Cycle affected
• Appearance/cause of death
Diastole is affected in this disease that results from ASYMMETRIC INTERVENTRICULAR HYPERTROPHY this leads to obstruction of Ventricular OUTFLOW also known as Idopathic Hypertrophic Subaortic Stenosis (IHSS)
Hypertrophic Cardiomyopathy
• Who is affected?
• Root etiology?
• what is the actual cause of death?
- 1/500 people are affect, and adults and children are affected equally
- 100% Genetic and many different proteins may be defective but most often it is ß-MYOSIN HEAVY CHAIN that gets affected
- Actual cause of death is Arrhythmia
What parameter of heart function is most affected in patients with hypertrophic cardiomyopathy?
• why are these patients predisposed to Arrhythmia?
• Key Histological Finding
• End Diastolic Volume is reduced because of septal enlargement in the left ventricle ultimately leading to reduced cardiac output
- Excess collagen deposited between myocytes prevents communication
- myocytes should be aligned in parallel however in Hypertrophic Cardiomyopathy they are swirls
What is the function of the ß-myosin heavy chain?
KEY COMPONENT of the SARCOMERE
***Note: most clinical findings related to Hypertrophic Cardiomyopathy are related to DECREASED COMPLIANCE AND FILLING OF LEFT VENTRICLE
Restrictive Cardiomyopathy
• Size Changes
• Gross Findings
• Etiology of Gross Findings
Size is NOT really affected in restrictive cardiomyopathy except for Bi-atrial dilation due to resticted movement of ventricle
• Myocardium will be firm
What type of cardiomyopathy is associated with HFE gene mutation?
• Symptoms Seen in these patients, cause?
• Primary or secondary?
RESTRICTIVE Cardiomyopathy of the LEFT VENTRICLE
HFE gene mutation = Hepcidin protein = HEREDITARY HEMOCHROMATOSIS => no Hepcidin means ferroportin stays upregulated and Iron gets deposited into tissue including the Heart
• patients have Liver Cirrhosis, Pancreatic Problems, Heart Problems, Reproductive Problems, and Skin Color Changes
What phase of the heart cycle is affected by hereditary hemochromatosis?
Diastole due to failure of stiffened ventricle to expand - this is what makes it a RESTRICTIVE Cardiomyopathy
True or False, Iron Overload Cardiomyopathy is the same as hereditary hemochromatosis and they are both considered restrictive cardiomyopathies.
FALSE, iron overload cardiomyopathy (secondary to lots of blood transfusions etc.) is just considered a dilated cardiomyopathy now instead of a restrictive one like Hereditary Hemochromatosis
What Three NON-viral pathogens are commonly associated with Cardiomyopathy?
•what kind of cardiomyopathy is implicated?
3 non-viral pathogens:
•Toxoplasmosis gondii
• Borrelia burgdoferi
• Trypanosoma cruzi
Which should be higher on you differential viral infectious myocardiditis or bacterial infectious myocarditis?
• What will you be looking for on biopsy?
*VIRAL infectious myocarditis is much more common (should be higher on you dd)
• Since the most common cause is viral you will usually see Lymphocytic Infiltrate
What will be the heart’s gross appearance in any type of infective myocarditis?
• microscopic appearance?
Gross:
• May be NORMAL or DIALATED
• May be Flabby and pale
• Mural Thrombi may be present
Microscopic Appearance
• Inflammatory infiltrate(lymphocytes-viral, neutrophils-bacterial)
• edema
• myocyte injury
A South American (who lives in a house with a thatched roof) comes in with an infectious myocarditis. What should pathogen should you suspect?
• diagnosis?
• carrier?
Trypanosoma cruzi - protazoan is probably the pathogen to blame
- *Dx: Chagas Disease
carrier: Reduviid Bug**
**note this diagnosis is typically made on the basis of a history and a peripheral blood smear
What would you expect to see if you biopsied the heart of someone with Chagas disease?
Trypanosomes (little fish egg looking gametes) are bundled up inside myocytes
Surrounding infected myoctes will be inflammatory infiltrate of NEUTROPHILS, LYMPHOCYTES, MACROPHAGES, EOSINOPHILS (occasionally)
What type of infectious myocarditis might be aqcuired by a pregnant lady changing the litter box?
• Other people who might get this?
Toxoplasma gondii - obligate intracellular parasitic PROTOZOAN
•Preganant women and heart transplant patients contract this most often
• NOTE: in transplant patients its most often a reactivation of a latent infection - most ppl. around cats are carriers
What is the histological appearance of Toxoplasma gondii?
pseudocyst containing BRADYZOITES of T. gondii appears IN myocardial cell
Borrelia burgdorferi
• type of pathogen?
• Carrier?
• Disease caused?
• Tale-Tale Sign?
Borrelia burgodorferi - bacteria that causes lyme disease. This is typically carried Ixodes scapularis (black legged tick) and Ixodes pacificus (WESTERN black legged tick)
• sign = Target Rash
What are 3 causes of NON-infectious myocarditis?
• Immune mediated (e.g. SLE)
• Hypersensitivity/Drug Mediate
• Giant Cell Myocarditis
T or F: Drug hypersensitivity reactions commonly lead to non-infectious myocarditis.
FALSE, these reactions very rarely cause CHF or death
Giant Cell Myocarditis
• Microscopic appearance
• relation to Giant Cell Vasculitis
• Px
Microscopically inflammatory infiltrate with multinucleated GIANT CELLS are seen. FOCAL and often EXTENSIVE NECROSIS is seen.
**This is NOT a progressive form of temporal vasculitis
POOR PROGNOSIS
What are two causes of PERICARDIAL (not myocardial) disease?
• what is the common result of both?
Effusions and inflammatory conditions both result in FIBROSIS AND CONTRICTION
What are some primary and secondary causes of Pericarditis?
• Frequency?
Primary pericarditis - UNcommon
• Viral
• concurrent MYOcarditis
Secondary pericarditis
• Uremia - COMMON CAUSE
• Autoimmune Diseases (Rheumatic Fever, and SLE)
• Metastasis
What causes Uremeia and what condition is this associated with?
Uremia - causes 2° PERICARDITIS
• associated with Renal dysfunction - causing fluid, electrolyte, metabolic, and hormonal abnormalities