Valvular Heart Disease Pathology and Clinical Flashcards
What is the purpose of cardiac valves?
What are the different types of valves in the heart?
To maintain unidirectional flow of blood
There are
SEMILUNAR valves (aortic and pulmonary) and
ATRIOVENTRICULAR valves (mitral and tricuspid)
what are the two main categories of valvular heart disease? How do they usually occur?
Stenosis (failure of a valve to open completely):
- chronic process affecting a valve cusp
and
Insufficiency (failure to close completely):
- Functional regurgitation of valvular incompetence due to disruption of supporting structures
- Intrinsic disease of valve cusps
What are the major valvular diseases discussed?
Congenital: Bicuspid aortic valve (most common)
Acquired:
Aortic stenosis: senile calcific aortic stenosis
Aortic insufficiency: Dilation of ascending aorta related to HTN and aging
Mitral stenosis: Rheumatic heart disease
Mitral insufficiency: Myxomatous degeneration
What are different examples of calcific valvular diseases?
What is it?
Calcific aortic stenosis and Mitral annular calcification
Dystrophic calcification- damage causing wear and tear complicated by deposits of calcium phosphate?
Calcific Aortic Stenosis (AS)
When does it occur?
What are the clinical effects?
What is the treatment?
Calcific Aortic Stenosis (AS)
5th/6th decades-biscuspid, unicuspid valves (assoc w/ Notch gene)
8th/9th decades- normal valves (“senile”)
Clinical effects:
LV: increased pressure causes hypertrophy
Angina, ischemia, CHF
Syncope
Death for 50% within 2 years
Treatment: valve replacement
Mitral Annular Calcification
What is it?
Who gets it?
Why is it bad?
Mitral Annular Calcification
Degenerative calcific deposits on fibrous ring, at base of valve
Occurs in women older than 60 yo, increased in pt. with myxomatous valves or elevated LV pressure.
Usually does not affect fxn but calcifications are sites for thrombi/infection
Myxomatous Degeneration of Mitral Valve (prolapse)
What is it?
In who does it occur?
What are the complications?
How does it happen and Assoc w/ what?
Clinical features?
Myxomatous Degeneration of Mitral Valve (prolapse)
One or both leaflets enlarged, hooded, redundant, floppy (myxoid). Prolapse or balloon back into left atrium during systole
Occurs in Young women
Usually no serious complications but can have regurgitation. Infective endocarditis, mitral insufficiency, thrombi on atrial surfaces leading to stroke or other systemic infarcts due to emboli, arrythmias leading to sudden death.
Unknown pathogenesis but probably developmental anomaly of connective tissue. Associated with Marfan syndrome (fibrillin gene mutation) and other hereditary disorders.
Clinically presents with mid systolic click on auscultation when asymptomatic or late systolic/holosystolic mumur when regurgitation happens
Acute Rheumatic Fever
When does it occur?
Most important complication?
How does it present?
Acute Rheumatic Fever
Follows episode of Group A Beta-hemolytic Streptococcal (pyogenes) pharyngitis
Most important complication is the progression to chronic valvular dysfunction (mitral stenosis)
Presents as widely disseminated inflammatory lesions in many sites:
Pancarditis (all three layers)
Bread and butter pericarditis
Myocarditis w/ Aschoff bodies
Endocardium and left sided valves w/ fibrinoid necrosis and verrucae
Subendothelial (MacCallum) plaques: irregular fibrous thickening of endocardium)
What are Aschoff Bodies?
Classic lesion of Acute Rheumatic Fever
Foci of swollen eosinophilic collagen surrounded by T lymphocytes, plasma cells, and plump macrophages- Anitschkow cells (caterpillar cells)
What happens in Chronic rheumatic heart disease?
What is the major effect?
Organization of inflammation and fibrosis leads to>
Thickened valve leaflets
Fusion of commissures (fishmouth or buttonhole deformities)
Fusion/thickening of chordae tendinae
Major effect is mitral stenosis, leads to left atrial dilatation (someitmes thrombus formation). REDUCED CARDIAC OUTPUT b/c mechanical obstruction prevents filling of LV
Pulmonary congestion, eventual right ventricular hypertrophy, and right sided heart failure.
To what extent are the different valves affected by chronic rheumatic heart disease?
Mitral valve alone (65-70%)
Mitral and aortic (25%)
Tricuspid less often
Pulmonary rare
What is the pathogenesis behind Rheumatic heart disease?
What is the diagnosis for this?
Hypersensitivity reaction induced by group A streptococci
Antibodies against M protein cross react w glycoprotein antigens in heart, joints, and other tissues.
Diagnosis through Jones criteria:
Preceding Group A strep infection
2 major manifestations or 1 major and 2 minor
For diagnosis of Rheumatic heart disease, (2 major or 1 major 2 minor) and preceding Group A strep infection
What are the major manifestations?
and
What are the minor manifestations
Migratory polyarthritis (large joints)
Carditis- pericardial friction rub, weak heart sounds, tachycardia, arrhythmia
Subcutaneous nodules -rare (extensor surfaces of joints)
Erythema marginatum of skin- rare (trunk)
Sydenham chorea (involuntary purposeless, rapid movements)
Minor: non specific signs and symptoms of:
fever
arthralgia
elevated acute-phase reactants
What is a specific biomarker clinical feature of acute rheumatic fever in regards to gropu a beta hemolytic strep?
ASO titers and antibodies to DNAase B
(anti-Streptolysin O) and DNAase are protein produced by group a strep
Prognosis for acute rf?
Prognisis for chronic?
Acute: good for primary attack. increased vulnerability to reactivation
Chronic: Years or decades after initial episode. Valvulitis. Surgical repair of valves improves outlook
What are the two basic clinical forms of infective endocarditis?
Acute: Highly virulent organism, normal valve, 50% mortality
Necrotizing ulcerative invasive infection requiring surgery
Subacute: Low virulence, deformed valve
Less destructive lesions, respond to antibiotics
What are the factors for getting infective endocarditis?
Cardiovascular abnormalities (RHD, myxomatous mitral valve, calcific valvular stenosis, artificial valves)
Host factors (Neutropenia, immunodeficiency, malignancy, diabetes, alcoholics, and IV drug users)
Common causative agents of infective endocarditis
Strep viridans for 50-60% of cases of infected deformed valves
Staph aureus is 10-20% of overall infective endocarditis (most common in IVDA)
What are the major and minor clinical criteria of bacterial endocardiits?
Major:
Positive blood cultures
ECG findings
New valvular regurgitation
Minor:
Predisposing heart lesion or IVDA
fever
Uncommon finding sfrom septic emboli
Complications of bacterial endocarditis?
Treatment?
Valvular insufficiency or stenosis and possible heart failure
Myocardial abscesses and possible perforation
Embolic complications from vegations break off
Glomerulonephritis
Treatment: IV antibiotics, valve replacement if necessary, prophylactic antibiotics after valve damage
What are examples of non infective vegetations and describe them.
Nonbacterial thrombotic endocarditis
Depositions of small masses of fibrin, platelets, and other blood products on leaflets occuring in debilitated patients. Can results in emboli and infarcts.
Caused by hypercoagulable states, assoc w mucin producting adenocarcinomas.
Sterile nondestructive noninflammatory small 1-5 mm.
Libman-Sacks endocarditis-a primary antiphospholipid syndrome
Systemic lupus erythematosus.
Mitral and tricuspid valves involved.
Antiphospholipid antibodies present.
Either or both sides of leaflets may also be on endocardium. Presents as 1-4 mm verrucae w/ fibrinous material may have intense inflammation
What is carcinoid syndrome?
How does it present?
What happens in the heart?
What is the exact cause?
Caused by carcinoid tumors that produce serotonin kallikrein bradykinin histamine prostaglandins and tachykinins.
Presents as flushing, cramps, nausea, vomiting, diarrhea
(serotonin and bradykinin inactivated by MAO in pulmonary vasculature AND also inactivated by passage through functioning liver.
Half of patients get plaque like fibrosis of right heart endocardium and valves. Usually on right not left b/c of inactivation of mediators by MAO in lung.
Exact cause unknown. Related to endothelial injury caused by vasoactive agents.
What are complications of artificial valves?
Mechanical prosthesis:
Thromboembolic complications
Infective endocarditis
Bioprosthesis:
Structural deterioration (half need replacement by 15 yrs)
Infective endocarditis
For Aortic Stenosis, what are the two major etiologies?
For one of the etiologies, age plays a factor. How so?
Calcific degeneration
<65= bicuspid valve
>65= tricuspid valve
<30=congenitally abnormal valve
Rheumatic
almost always involves mitral valve as well
What happens with severe aortic valve stenosis in regards to pressures
Left ventricle increases dramatically in pressure whereas the aortic decreses. Left atrial pressure also increases
On a graph of LVP by LVV you get a right and upward shift
How do you diagnose aortic stenosis?
Physical exam- Sustained LV impulse w/ little to no displacement. Weakened and late carotid impulse. Absent A2 or paradoxically split A2, murmur is systolic crescendo decrescendo (later peaking/worse stenosis). Heard at the base of the heart or the right upper sternal border radiating to the carotid arteries.
CXR- Little cardiac enlargement due to LVH. Post stenotic dilation of the ascending aorta. Calcification of the aortic valve.
EKG- Shows left ventricular hypetrophy
Echocardiogram-Shown decreased valve area
Cardiac catheterization- Peak to peak between LV and Aortic pressures.
Prognosis for Aortic stenosis?
Key point is when symptoms begin to develop
Angina (5 yr mean survival)
Syncope (3 yr mean survival)
CHF (2 yr mean survival)
Treatment for aortic stenosis?
What is a classic presntation of aortic stenosis on physical exam?
Valve replacement for when severe aortic stenosis WITH SYMPTOMS occurs.
Systolic crescendo decrescendo murmur at the right upper sternal border radiating to the carotids
What are causes of aortic regurgitaiton?
Abnormalities of the valve leaflets
- Congenital
- Endocarditis
- Rheumatic
Dilation of the aortic root
- Aortic aneurysm
- Aortic dissection
- Annuloaortic ectasia
- Syphilis
What is aortic regurgitation?
What is it acutely?
What is it chronically?
Part of the blood the LV ejects into the aorta during systole returns to teh LV in diastole across an incompetent valve.
Resulting in VOLUME OVERLOAD of the left ventricle
Acute: Left ventricle normal size with low compliance. Diastolic pressure rises quickly. This backs up to the left atrium and into pulmonary vasculature. Results in pulmonary congestion and or edema (surgical emergency)
Chronic: Left ventricle undergoes compensatory adaptation in response to regurgitation. There is volume overload and some pressure overload of teh left ventricle. Ventricle dilates over time. Left ventricle compliance increases. Reduced pressure to the left atrium and pulmonary vasculature
Patient complaints w/ aortic regurgitaiton?
Physical signs?
Complaints of
- dyspnea on exertion
- fatigue
- Decrased exercise tolerance
- chest pain
Physical signs:
Hyperdynamic pulses, head bobibng, water hammer pulse.
Widened pulse pressure (diastolic bp less than half of systolic bp)
Decrescendo diastolic murmur–increases w increased SVR, heard best at end expiration w patient leaning forward
Austin Flint murmur a diastolic rumble
What shows on Chest x ray for aortic regurgitation
Enlarged left ventricular silhouette (chronic)
Acute less likely to show this but more to show pulmonary vascular congestion.
How do you treat aortic regurgitation?
For acute: surgical emergency w/ immediate surgical replacement
For chronic:
If asymptomatic and normal LVEF (>50%): periodic followup with echocardiography and consider afterload reduction w calcium channel blocker or ACE inhibitior if patient has HTN
If asymptomatic and low LVEF (<50%): Refer for surgery for valve replacement
If symptomatic and normal LVEF: Refer to surgery for valve replacement
What are the etiologies for mitral regurgitation?
Organic (primary):
Myxomatous disease /MVP (degenerative)
Rheumatic valve disease
Endocarditis
Congenital (cleft leaflet)
Functional (secondary):
Ischemic CM
Dilated CM
Hypertrophic CM
What are the signs of acute mitral regurgitation?
Normal LA size and compliance
High left atrial pressure
High pulmonary venous pressure
Pulmonary congestion and edema
See prominent V waves on catheterization
Acute mitral regurgitation is considered medical emergency
Signs of chronic mitral regurgitation?
Increased left atrial size and compliance
More normal left atrial and pulmonary venous pressures
Lower forward cardiac output
See increased left ventricular size
Eventual systolic dysfunction over time
* hear a holosystolic murmur at the apex of the heart upon auscultation
MAnagement of acute mitral regurg
Management of chronical mitral regurg
acute: stabilize the patient w/ diuretics and vasodilators and also depending on the cause, consider emergent surgery for management
Chronic: if asymptomatic continue to monitor. If symptomatic and severe mitral regurgitation see about repair or replacement of the valve (repair preferred)
IF there is severe left ventricular dysfucntion often little can be done
For the papillary muscles, what portions supply chordae to what parts of the leaflets
What are the blood supplies
2 main papillary muscles w several heads
Anterolateral portion provides chordae to the anteroalteral half of both mitral leaflets
Posteromedial portion provides chordae to the posteromedial half of both mitral leaflets
Posteromedial portion blood supply from right coronary artery.
Anterolateral portion blood supply dual supply
What etiology causes mitral stenosis?
Mostly rheumatic fever
rare causes: congenital stenosis/calcification of the mitral annulus/endocarditis with large vegetattions obstructing valve orifice
What is the normal valve area?
What is seen w/ mitral stenosis?
3-4 cmsquared in normal
in Mitral stenosis, MVA<2cmsquared
symptoms of mitral stenosis
Dyspnea and reduced exercise capacity
In milder, no symptoms at rest only w exertion or increase dhr activities
in more severe, shortness of breath occurs at rest, patients develop symptoms of heart failure w orthopnea, paroxysmal nocturnal dyspnea.
Also signs of rightsided heart failure w jugular venous distension. hepatomegaly ascites, edema
Rare symptoms: hoarseness and hemoptysis
treatment for mitral stenosis
Duretics if vascular congestion
beta blcoekrs calcium channel blockers digoxin if atrial fibrilliation
chronic anticoagulation if atrial fibrilliaton present
IF medical not working or if significant pulmonary hypertension then Balloon valvulplasty or valve replacement
