Heart II Flashcards
Most common cause of rhythm DOs is:
Ischemic injury
Sick sinus syndrome
SA node is damaged —> bradycardia
AFib
Myocytes depolarize sporadically (atrial dilation) w/ variable transmission thru AV node —> irregular irregular HR
What is a heart block?
1st, 2nd and 3rd degree heart blocks
Dysfunctional AV node
1st - prolonged PR interval
2nd - intermittent trasmission
3rd - complete failure
What hereditary pattern causes most genetic arrythimias?
AD
What are channelopathies?
What other diseases are associated? (2)
Mutations in genes that are required for normal ion channel function.
Skeletal m. DOs and DM
Abnormalities in gap junction structure or spatial relationship can cause:
Arrythmias (ischemic heart DZ, cardiomyopathies, myocyte hypertrophy, inflammation, amyloid, etc.)
Long QT syndrome causes dysfunction in what?
LOF mutations in K+ channels
GOF mutations in Na+ channels
Often seen in swimmers.
SCD is unexpected death from a cardiac cause, either….
80-90% of successfully resuscitated pts show….
Without SX, or within 1-24 hrs of SX onset.
Show no lab or ECG changes.
What is the most common precipitating cause of SCD?
80-90% are from CAD, usually >75% stenosis of one or more of the 3 main coronary aa.
Unfortunately, SCD is often the first manifestation of ischemic HD.
SCD is due to a…
SCD is due to a fatal arrhythmia most often arising from an ischemia-induced myocardial irritability.
Left-sided (systemic) Hypertensive heart DZ (HHD)
Pressure overload causes LVH —> LV wall is *concentrically thickened (>1.5 cm and >500 mg).
Diastolic dysfunction may result in LA enlargement, and can lead to AFib.
Might also lead to CHF.
Right-sided (pulmonary) Hypertensive heart DZ (HHD)
Arises in the setting of pulm. HTN.
Acute cor pulmonale may arise from a large pulmonary embolus (marked dilation of the RV w/o hypertrophy.
Most common cause of pulmonary HTN is:
Left-sided HD
What are 3 pathologic changes that occur to cardiac valves?
Damage to collagen that weakens the leaflets (ex: MVP)
Nodular calficiation (ex: calcified aortic stenosis)
Fibrotic thickening (ex: rheumatic heart DZ)
Functional regurgitation
Ex:
Incompetence of a valve stemming from an abnormality in one of its support structures, as opposed to a primary valve defect.
Ex: functional MV regurg, which is important in IHD and dilated cardiomyopathy
How is blood flow to a valve impacted when there is pathologic changes to it?
Usually, valves get nourishment via diffusion. However, if the valve becomes to thick, angiogenesis must occur and leads to an increase risk of valvular insufficiency.
Valvular HD may present with: (2)
Stenosis or insufficiency
Stenosis impedes flow in which direction?
Chronic stenosis may lead to:
Impedes forward flow. Valve does not open all the way.
Chronic stenosis may lead to pressure overload hypertrophy —> CHF.
Insufficiency allows flow in which direction?
Chronic insufficiency may lead to:
Allows flow in the reversed direction. Valves don’t close completely.
Chronic insufficiency may cause volume overload hypertrophy —> CHF.
Mitral stenosis is caused by:
Postinflammatory scarring (rheumatic heart DZ)
Mitral regurg is caused by: (3)
Abnormalities of leaflets and commissures
MVP
Drugs (fen-phen)
Aortic stenosis is caused by: (4)
Calcification of congenitally deformed valve
Postinflammatory scarring (RHD)
Abnormalities in tensor apparatus
Abnormalities of LV and/or annulus
Aortic regurg is caused by: (4)
Aortic insufficiency: dilation of ascending aorta.
Postinflammatory scarring (RHD)
Syphilitic aortitis
Marfan’s syndrome
What is the most common valve abnormality?
What is the pt demographic?
Calcific aortic stenosis
Prevalence increases w/ age (usually 60-80 y/o)
What causes calcific aortic stenosis?
Which valves tend to show an accelerated course? What type of cells are within the valve?
What causes the incomplete opening of the valve?
“Wear and tear” associated w/ chronic HTN, hyperlipidemia, inflammation. Cusps may fuse together.
Bicuspid aortic valves (from fusion). Osteoblast-like cells —> ossification.
“Mounded calcifications in cusps”.
What are the SX of calcific aortic stenosis?
Structurally, what happens to the heart?
What is the course of the disease?
SX: angina, CHF, syncope.
LVH develops from increased pressure.
Death within 5 yrs of angina, 3 yrs of syncope, 2 yrs of CHF. Must be replaced surgically.
Aortic valve should have _________, but often have ______ in aortic calcification.
3 leaflets, but in aortic calcification they may fuse together (or vise versa).
Mitral annular calcification occurs where on the valve?
What is its effect on valve function? What are the exceptions?
What can the calcified nodules become?
Deposits occur mostly at the base of the leaflets on the fibrous annulus.
Normally does not affect valve function (because it is at base and not on leaflet itself), but there are exceptions: *arrhythmia (may cause sudden death), regurg, and stenosis.
Nodules can become sites for thrombus formation or infective endocarditis.
Which patient population is most at risk for mitral annular calfication?
F>M, > 60 y/o w/ MVP
What happens functionally with MVP?
Who is most affected?
What is classically heard on auscultation?
MV leaflets prolapse back into LA during systole.
7:1, F>M
Mid-systolic click
What syndrome can predispose a pt to MVP?
Marfan’s, due to loss of CT —> floppy valve.
What is myxomatous degeneration?
Deposition of proteoglycan and elastin disruption leading to thick and rubbery leaflets that occurs in an MVP
What is the characteristic anatomic change in an MVP?
Interchordal ballooning (hooding) of the MV leaflets
SX of MVP
How can it be Tx?
ASX usually, but may include:
Chest pain, DOE
Or more serious problems, like:
Infective endocarditis
Mitral insufficiency
Embolus
Arrhythmias
Valve repair/replacement surgery
Rheumatic fever occurs following what?
What is the progression of it?
What is the pathogenesis?
How is it tested for?
Following a pharyngeal infection w/ Grp A strep.
May include a carditis component acutely, and over time may evolve to chronic RHD.
Immune response to strep M proteins that cross react w/ cardiac self-Ags.
Anti-streptolysin O and anti-DNase B.
What are some classic SX w/ RF? (4)
Pancarditis, migratory polyarthritis, erythema marginatum, Syndenham chorea
What are Aschoff bodies?
T cells, plasma cells and Mo called Anitschkow cells that appear in a pt. w/ pancarditis as a result of RF.
3 major cardiac features in a pt. w/ acute RF
Pancardititis (w/ Anitschkow cells)
FIbrinoid necrosis of endocardium and left-sided valves
Veerucae (vegetations) on left sided valves
What occurs structurally in chronic RHD? (3)
Mitral leaflet thickening and fusion of commissures which leads to mitral stenosis.
LA enlargement (can lead to arrhythmia,thrombus, etc)
RV hypertrophy
Acute infective endocarditis
Tx?
Rapidly progressing, destructive infection of a previously normal valve.
Requires surgery and ABX.
Subacute infective endocarditis
Tx?
Slower progressing infection of a previously deformed valve (ex: chronic RHD).
ABX usually does the trick.
Predisposing conditions to IE (2)
Valvular abnormalities
Bacteremia
Classic feature of IE
Friable (can lead to septic emboli), bulky and destructive valvular vegetations
Which valves are more often affected in IE?
What about the other side of valves?
Left-sided valves more common.
IE of right-sided valves often as a result of IVD users.
SX of subacte IE
SX of acute IE
Nonspecific usually: fever, wt. loss, fatugue, flu-like SX.
Rapid onset of SX.
SX of acute endocarditis
Fever, chills, weakness, fatigue
Organisms most often implicated in IE and in what setting are they active? (4)
S. viridans (valve abnormalities)
S. aureus (normal or abn valves, IVD users)
S. epidermidis (prosthetic valves)
HACEK group
How do the vegetations look in RHD vs. IE vs. NBTE?
RHD - warty, at line of closure
IE - large, irregular
NBTE - small, line of closure
A murmur is usually associated with which sided lesion in IE?
Left
Acute IE
Mortality Virulence of organism Valve structure Lesion type What is seen at a micro level? Ring abscesses? Emboli?
Mortality - <6 wks w/ 50% mortality Virulence of organism - highly virulent Valve structure - normal valve Lesion type - necrotizing, ulcerative What is seen at a micro level? Organisms Ring abscesses? Yes Emboli? Yes, possibly mycotic aneurysm, too.
Subacute IE
Mortality Virulence of organism Valve structure What is seen at a micro level? Ring abscesses? Emboli?
Mortality - most survive w/ Tx Virulence of organism - less virulent Valve structure - abnormal valves What is seen at a micro level? Calcification and chronic inflammatory cells Ring abscesses? No Emboli? No
Minor features used to DX IE (4)
Subungal/splinter hemorrhages Janeway lesions (red spots on feet) Roth spots (fundoscopic exam) Osler nodes (on hand)
Nonbacterial thrombotic endocarditis (NBTE) def:
Associated with?
A source of?
Small, sterile thrombi on cardiac leaflets along line of closure.
Associated w/ mucinous adenocarcinomas.
Source of embolism.
Carcinoid heart syndrome SX
What might be released by a carcinoid tumor?
Systemic disorder marked by flushing, diarrhea, dermatitis and bronchoconstriction. Paraneoplastic syndrome.
Serotonin (correlated w/ 5-hydroxyindoleacetic acid)
Carcinoid heart DZ has manifestations at:
Usually the right endocardium and valves. The left side is protected due the pulmonary vascular bed degrading the mediators.
Dilated cardiomyopathy
LV EF:
Cause of phenotype (3)
LV EF: <40%
Cause of phenotype: genetic, alcohol, hemochromatosis** (hereditary hemochromatosis).
*most common
Hypertrophic cardiomyopathy
LV EF:
Cause of phenotype (1)
LV EF: 50-80%
Cause of phenotype: genetic
Restrictive cardiomyopathy
LV EF:
Cause of phenotype (1)
LV EF: 45-90%
Cause of phenotype: amyloidosis
Dilated cardiomyopathy (DCM) def:
Pathogenesis:
Progressive cardiac dilation and systolic dysfunction w/ dilated hypertrophy.
AD mutation
DCM morphology (3)
Dilation of all chambers
Mural thrombi common
Functional regurg
DCM presentation:
Age:
Progression:
Complications (2):
Age: manifests at 20-50 yo
Progression: progressive CHF -> DOE, fatigue and dec. EF (<25% is end stage)
Complications (2): arrhythmia (sudden death), embolism
What kind of CM is Takotsubo CM?
Pathogenesis:
Demographic:
SX:
Functional changes to heart:
DCM.
Excess catecholamines released following extreme emotional stress.
> 90% women from 58-75 yo.
SX similar to MI.
Apical ballooning of LV w/ contractile dysfunction.
Most common protein mutation in CMs:
Titin
Arrhythmogenic right ventricular CM (ARVC) has what 2 features:
What do they cause?
What is the heredity? What is the defective protein?
RV failure and arrhythmias.
Causes Vtach or VFib and causes sudden death.
AD, defective cell adhesion protein in desmosomes that link myocytes.
What is Naxos syndrome?
What is the defective protein?
An ARVC w/ hyperkeratosis of hands and feet.
Plakoglobin (a desmosome-assoc. protein).
What happens to the myocardium of the RV wall in ARVC?
It is replaced by adipose and fibrosis
Hypertrophic CM def:
A genetic DO that leads to myocardial hypertrophy and diastolic dysfunction -> dec. stroke vol and ventircular outflow obstruction.
What is mutated in hypertrophic CM?
Sarcomeric proteins, usually beta-myosin heavy chain
Morphology of hypertrophic CM (2)
Septal hypertrophy
Myocyte disarray
Murmur heard in hypertrophic CM
Harsh systolic ejection murmur
Consequences of extensive hypertrophy
Myocardial ischemia LA dilation and mural thrombus Dec CO and increased pulm congestion Arrythmia Sudden death
Restrictive CM leads to what kind of dysfunction: systolic or diastolic?
Caused by:
What is enlarged?
Diastolic, due to dec. ventricular compliance.
Deposition of amyloid or fibrosis.
Atria are enlarged, because the ventricle isn’t filling properly.
What kind of amyloid will accumulate in restrictive CM?
What is it called if it is systemic vs. only the heart?
Insoluble beta-pleated sheets.
Systemic: myeloma
Heart: transthyretin
What infectious agents cause myocarditis?
Coxsackie A and B (most common) Trypanosoma cruzi (causes a mixed inflammatory cell infiltrate)
What are some non-infectious causes of myocarditis? (3)
RF
SLE
Drug hypersensitivity
Most common type of Pericardial DZ
SX:
What will be heard on auscultation?
Fibrinous (dry, granular) and serofibrinous (turbid fluid w/ WBCs).
Pleuritic chest pain.
Loud pericardial friction rub.
Primary cardiac tumors are all __________.
2 main ones to know:
Benign.
Myxoma*, angiosarcoma.
Where are myxomas usually found?
What is a common gene association?
What does the tumor look like?
Near fossa ovalis.
GNAS1
Globular hard mass marked w/ hemorrhages w/ a gelatinous appearance.
What are some SX of myxomas
Ball-valve obstructions
Embolus
Constitutional SX
What is the “wrecking ball” feature of a myxoma?
What is heard on auscultation?
The intermittent obstruction during systole of the AV valve. May cause damage to leaflets.
Tumor “plop”
What mediator is responsible for the constitutional SX from a myxoma?
IL-6
The most prequent primary tumor of the pediatric heart is:
Rhabdomyoma
2 most common DZs resulting in a heart transplant
DCM
IHD
What is the most important long-term limitation of transplantation?
Allograft arteriopathy
-stenosing intimal proliferation
2 major disease complications that can follow transplant
Silent MI due to denervated heart (no angina)
EBV associated B cell lymphoma due to chronic T cell suppression
