Flashcards in Valvular Disease and Cardiomyopathies Deck (63):
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?
1. degenerative calcification of tricuspid aortic valve
2. degenerative calcification of bicuspid aortic valve
3. chronic rheumatic valvulitis
What are the 5 main causes of aortic regurgitation?
1. chronic rheumatic valvulitis
2. infective endocarditis
3. syphilitic aortitis
4. rheumatoid arthritis
What is the major cause of mitral stenosis?
chronic rheumatic valvulitis
What are the 8 causes of mitral regurgitation?
1. chronic rheumatic valvulitis
2. infective endocarditis
3. myxomatous mitral valve
4. Fen-Phen induced valve fibrosis
5. ruptured papillary muscle
6. ruptured chorda tendinae
7. LV enlargement
What are the 3 types of calcific aortic stenosis?
1. degenerative calcification of a normal tricuspid valve
2. degenerative calcification of a bicuspid valve
3. Chronic rheumatic aortic valvulitis
Why are some aortic valves bicuspid? (normal is tricuspid)
1. 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)
2. 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?
1. Angina- because heart can't perfuse LV well
2. Syncope- poor perfusion of the brain
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
1. women 7x more than men
2. People with hereditary defects in connective tissue (Marfan, EDS)
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?
2. infective endocarditis
3. 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?
1. arthritis - migratory polyarthritis (joint to joint)
2. 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?
1. serologic evidence of a previous GABHS infection (anti-streptolysin O or anti-DNAase Ab)
2. At least two of the following Jones Criteria
- subcutaneous nodules
- erythema marginatum
- chorea (involuntary movements)
3. one jones criteria and 2 non-specific signs:
- 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?
1. Jet streams from abnormal valves allow platelet-fibrin deposits on the valves
2. Bacteria is introduced via dental or GI/GU surgery or through breaks in the skin, IV drug use, etc)
3. 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?
1. blood cultures
3. 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?
4. local myocarditis
5. perforation of the valve
What are the 3 common agents of infective endocarditis?
1. Staph aureus - normal valves
2. viridians strep- damaged valves
3. HACEK (haemophilis, actionbacillus, cardiobacterium, eikenella, kingella)
What valve tends to get infective endocarditis if there is an IV drug user?
Tricuspid because it is the first valve passed after entry of drugs/infection into the veins
What does it mean that the vegetation in infective endocarditis is friable?
There is little holding it together. It is just bacteria and fibrin so it can fragment and embolize relatively easily
What is marantic endocarditis?
What can they organize into?
When are they likely to occur?
Non-bacterial thrombotic endocarditis where sterile vegetations like fibrin, platelets and blood components collect on normal valves.
They can organize into strands called Lambl excrescenses.
They occur in hypercoagulable states (DIC, malignancy, ESCPECIALLY mucinous adenocarcinoma)
What is the difference between a primary and secondary cardiomyopathy?
Primary are confined to heart muscle while secondary are widespread, multi-organ
What are the three main categories of cardiomyopathies?
Which impair systole? diastole?
1. Dilated- impaired systole
2. Restrictive- impaired diastole
3. hypertrophic- impaired diastole
Dilated cardiomyopathy is the dilation of ____________ associated with _____ hypertrophy of the myocardium
dilation of all four chambers of the heart associated with eccentric hypertrophy of the myocardium
What are the microscopic changes noted in dilated cardiomyopathy? Are they diagnostic?
Hypertrophy and fibrosis which are non-specific changes and thus not diagnostic.
What are the 4 major causes of dilated cardiomyopathy?
1. viral infections
2. alcohol use
3. genetic abnormalities
4. peripartum state
What viral infections lead to dilated cardiomyopathy?
Coxsackie B and enteroviruses
What drugs can cause dilated cardiomyopathy?
What is wet beri-beri?
A thiamine deficiency that causes dilated cardiomyopathy
What are the five common genes mutated in dilated cardiomyopathy?
1-2. lamins A and C (structural proteins in the inner nuclear membrane)
3. the B-myosin heavy chain gene
4. dystophin (links cytoskeleton of striated muscle to ECM)
5. a-cardiac actin - links sarcomere to dystophin
What occurs due to the dilation of the LV?
1. CHF (systolic dysfunction) because LV cannot generate sufficient force to expel enough blood.
2. mitral insufficiency
3. abnormal cardiac rhythm
Describe the gross and microscopic morphology of hypertrophic cardiomyopathy.
1. thick interventricular septum
2. fibrosis on the outflow tract from septum striking the anterior leaflet of the mitral valve
1. myofiber disarray (pinwheel fibers)** diagnostic
3. sclerosis of vessels
What is the cause of most hypertrophic cardiomyopathies?
mutations in sarcomeric proteins with AD inheritance.
1. b-myosin heavy chain
2. myosin binding proteins C
3. Troponin I
This leads to inefficient contraction which can trigger hypertrophy
What occurs as a result of hypertrophic cardiomyopathy?
1. impaired diastolic filling-> decreased CO
2. increased pulmonary pressure (due to backup)
3. systolic ejection murmur due to outflow obstruction
4. ischemia due to inadequate coronary artery filling + hypertrophy
This leads to arrhythmia, CHF and sudden death
What is restrictive cardiomyopathy?
The ventricles are normal size (slightly enlarged) and the chambers are NOT dilated.
there is reduced compliance of the ventricle, however, due to the infiltration of :
granulomas in sarcoidosis, iron in hemochromatosis, amyloidosis, radiation fibrosis etc
What are the two variants of restrictive cardiomyopathy?
1. endomyocardial fibrosis- children and young adults in Africa where there is dense fibrosis of the endocardium and subendocardium reducing compliance and impairing filling during diastole
2. Loeffler endomyocarditis- dense fibrosis in the endocardium with eosinophilia and MBP damaging the tissues
What is arrythmogenic RV cardiomyopathy?
dilation of the RV associated with thin walls and fibrosis.
Present with right heart failure or sudden cardiac death
AD linked to chromosome 14
What is myocarditis?
How does it differ from infarction?
Inflammation of the heart which damages myocardium.
(Different from infarction because that is when damage to the heart causes inflammation)
What are the infectious causes of myocarditis? (5)
1. Viral - Coxsackie B, ECHO, flu, HIV, CMV, chlamydia and ricketssiae
2. bacteria- diphtheria, borellia (lymes)
3. fungi- candida
4. protozoa- trypanosoma cruzi (chaga). toxo
5. helminthes - trichinosis
What are immune-mediated causes of myocarditis? (4)
2. Rheumatic fever
3. post viral
4. drug hypersensitivity
What is lymphocyte myocarditis?
mononuclear infiltrates associated with cardiac myocyte necrosis. (viral CoxB in origin)
What is hypersensitivity myocarditis?
When do you usually see it
Eosinophils concentrate around vessels.
You see this when you change medications for a patient or start a new one
What is giant cell myocarditis?
Macrophages and multinucleated giant cells in the myocytes. HIGH MORTALITY
Patients with myocarditis can progress to _______.
What is pericarditis?
What are the three main types and what is the cause of each?
Inflammatory infiltrates in the pericardial sac which can be:
1. fibrinous (viral)
2. fibrinopurulent (bacterial)
3. fibrinohemorrhagic (malignancy)**
** harder recovery
Which pericarditis are considered acute?
What is the likelihood of recovery?
Fibrinous and fibrinopurulent
They can completely resolve but may cause scarring (which would make them chronic too)
What is it called if the fibrosis is chronic pericarditis is so severe that it impairs diastole?
If pericarditis was associated with uremia, what would the gross heart look like?
A piece of bread and butter that you dropped on the ground and then picked up
What are the clinical findings associated with pericarditis?
1. chest pain NOT related to exertion
2. friction rub
4. tamponade if there is a lot of fluid which inhibits diastole and LV filling
What are the 3 kinds of pericardial effusions and what are the causes of each?
1. Serous : CHF, hypoalbuminemia
2. Serosanguinous- trauma, malignancy, ruptured MI
3. Chylous- lymphatic obstruction
For pericardial effusions, slow accumulation can tolerate ___________ while rapid accumulation can only tolerate _______ before causing tamponade.
Slow= 1-2 L
Fast = 250-300 mL
What is the most common neoplasm of the heart?
Metastases from lung, lymphoma, breast, leukemia, melanoma, liver
What are the 6 primary neoplasms of the heart?
Are most benign or malignant?
Most are benign
4. papillary fibroelastoma
What is a myxoma?
Are they benign or malignant?
What makes them dangerous?
neoplasm in the LA near fossa ovalis that can be sessile or peduncelated
Soft with myxoid matric and myxoma cells that can fragment and embolize