Valvular Disease and Cardiomyopathies Flashcards
What is the difference between valvular stenosis and valvular regurgitation?
Are these pathologic processes acute or chronic?
Stenosis is obstruction of forward flow through a valve because it cannot completely open . It is almost always chronic.
Insufficiency (regurgitation) is backward flow because the valve cannot close all the way. It can be acute or chronic (acute can occur after papillary muscle infarction/rupture)
What are the 3 main causes of aortic stenosis?
- degenerative calcification of tricuspid aortic valve
- degenerative calcification of bicuspid aortic valve
- chronic rheumatic valvulitis
What are the 5 main causes of aortic regurgitation?
- chronic rheumatic valvulitis
- infective endocarditis
- syphilitic aortitis
- rheumatoid arthritis
- Marfan
What is the major cause of mitral stenosis?
chronic rheumatic valvulitis
What are the 8 causes of mitral regurgitation?
- chronic rheumatic valvulitis
- infective endocarditis
- myxomatous mitral valve
- Fen-Phen induced valve fibrosis
- ruptured papillary muscle
- ruptured chorda tendinae
- LV enlargement
- calcification
What are the 3 types of calcific aortic stenosis?
- degenerative calcification of a normal tricuspid valve
- degenerative calcification of a bicuspid valve
- Chronic rheumatic aortic valvulitis
Why are some aortic valves bicuspid? (normal is tricuspid)
- Congenital - 1.4% of the population have one large and one small cusp. The large is incomplete separation of two cusps (“true bicuspid” is when the leaflets are the same size)
- Acquired - following infective endocarditis, the healing can scar the commissure and fuse two leaflets
What is the progression of normal valve–> calcified valve?
What is the age of onset for symptoms of calcification in a normal tricuspid valve? Bicuspid?
Over time normal aortic valves acquire wear and tear damage (degeneration).
This damage is the nidus for calcium deposition
Tricuspid- 70 to 80 years
Bicuspid - 40-50 years
Aortic stenosis produces a ____________ overload of the ______ which results in _____________________.
pressure overload of the left ventricle which results in concentric LV hypertrophy
What are the 3 main clinical features associated with aortic stenosis?
- Angina- because heart can’t perfuse LV well
- Syncope- poor perfusion of the brain
- CHF
What is a myxomatous mitral valve?
What is the prevalence? Who does it affect most?
What chromosomes has it been linked to?
Ballooning of the mitral valve leaflets with enlarged thick rubberly leaflets. Chorda tendinae elongate and rupture
3-5% of the population
- women 7x more than men
- People with hereditary defects in connective tissue (Marfan, EDS)
16,11,13
If there is myxomatous mitral valve (mitral valve prolapse) what will you hear on the heart sounds?
You will hear a mid-systolic click
What does myxomatous mitral valve put patients at risk for?
- regurgitation
- infective endocarditis
- sudden death (RARE) due to ventricular arrhythmia (because the AV node is just next to the mitral valve)
Why could a myxomatous mitral valve potentially cause sudden death?
IT is right next to the AV valve. If it blocks conduction, then the ventrical would beat independently causing arrythmia
What is rheumatic valvular disease?
Who does it normally affect?
Complication that arises from rheumatic fever (a sequelae to GABHS pharyngeal infection).
Ab are developed agains M proteins of the GABHS that can cross react with glycoproteins in the human body
Children 5-15 after a pharyngeal strep infection (2-3 weeks after)
What are the 2 most prominent clinical manifestations of acute rheumatic fever?
- arthritis - migratory polyarthritis (joint to joint)
- carditis- peri, myo, endo or a combo of all 3
(endocarditis is a 1-2mm vegetation forming at the line of valve closure)
How is acute rheumatic fever diagnosed?
- serologic evidence of a previous GABHS infection (anti-streptolysin O or anti-DNAase Ab)
- At least two of the following Jones Criteria
- carditis
- migratory polyarthritis
- subcutaneous nodules
- erythema marginatum
- chorea (involuntary movements)
OR
- one jones criteria and 2 non-specific signs:
- fever
- arthralgia
- elevated acute phase reactants
Describe the morphology associated with acute rheumatic valvular disease?
What cells do you see?
Aschoff bodies- central degeneration zones with hypereosinophilic material infiltrated by T lymphocytes and Anitschkow macrophages (with large wavy chromatin)
What is the morphology of chronic rheumatic fever?
scarring of the valves (mitral then aortic)
Mitral- thick leaflets, thick/fused/shortened chorda tendinae, commissure fusion
Aortic- fusion at ALL commisures, thicken cusps
What changes in the heart can chronic rheumatic fever of the mitral valve cause?
The scarred, fibrotic, thick valve can lead to stenosis which will cause LA dilation and mural thrombi formation
What is the difference between acute and subacute infective endocarditis?
Acute- rapidly develops because of a highly virulent organism (s. aureus) on a normal cardiac valve. HIGH MORTALITY
Subacute- slow onset infection with prolonged course due to low virulence organism (strep) on an abnormal valve
How does infective endocarditis develop?
Who is most at risk?
- Jet streams from abnormal valves allow platelet-fibrin deposits on the valves
- Bacteria is introduced via dental or GI/GU surgery or through breaks in the skin, IV drug use, etc)
- platelet-fibrin deposits get infected by bacteria or organisms in the blood
People who are immune compromised (neutropenia, immunodeficiency, malignancy, DM, IV drug users)
If people have abnormal valves, what should they do before having surgery?
Antibiotic prophylaxis to prevent infective endocarditis
How are both forms of infective endocarditis diagnosed?
How is it treated?
- blood cultures
- Echocardiograph
- both can be associated with murmurs, petechiae in nail beds
Treated wit long courses of antibiotics because the valves are relatively avascular so it is hard to get high concentrations of the drug to the valve
What are 5 common complications associated with infective endocarditis?
- glomerulonephritis
- septicemia
- embolization
- local myocarditis
- perforation of the valve