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VALVULAR HEART DISEASE
Arthur C. Aufderheide, M.D.
Med 6655. Cardiovascular System
RHEUMATIC HEART DISEASE (RHD): ACUTE (1)
• Acute rheumatic fever
• Group A beta-hemolytic strep (pharyngitis). In only 3% of these, rheumatic fever develops 2-6 weeks later
• Strep and endocardium = shared antigen (M protein: M 18 ?) responsible for
virulence (molecular mimicry) capsular glycoprotein
RHEUMATIC HEART DISEASE (RHD): ACUTE (2)
• Clinical: brain (Sydenham’s chorea [St. Vitus’ dance]) –
purposeless, erratic motor movements joints, skin, heart, pancarditis
• Incidence: declining 1946 = 343 / 100,000 1986 = 0.3 / 100,000 But still in Third World
U.S.A. Why?
RHEUMATIC HEART DISEASE: ACUTE
• Pancarditis:
Myocarditis (Aschoff bodies)
collagen focal necrosis with granuloma
(histiocytic cells — multinucleate and
Anitschkow)
Endocarditis
Pericarditis (fibrinoid)
Myocardial Aschoff body
Ashoff body
Lymphs,macs,multinucleates
Anitschkow cells
ACUTE RHD: ENDOCARDITIS
• Valves: Mitral and aortic (tricuspid rare; pulmonary,
"never") Collagen necrosis:
surface thrombus ("verrucae") murmur
• Active inflammation may continue for years after other lesions heal
Endocardial Aschoff body
pericarditis
fibrinous
ACUTE RHD: LAB TESTS
• ASO (Anti-Streptolysin-O Titer — Todd test)
Others: anti-DNase B, antistreptokinase
• CRP (C-Reactive Protein)
• ECG ( P-R interval)
• None of above are specific for rheumatic fever
Minithroimbus on mitral cusp (Aschoff )
RHEUMATIC VEGETATIONS
RHEUMATIC VEGETATIONS
CHRONIC RHD: MITRAL STENOSIS (1)
• Most common. Mostly females. Post-rheumatic
fever.
• Thick, fibrous, calcified valve
• Functional defect: stenosis > regurgitation.
Lt. atrium fibrillation (big problem) stasis
thrombi emboli:
lung
systemic
MITRAL STENOSIS
Huge left atrium
Short chordae
CHRONIC RHD: MITRAL STENOSIS (2)
• Lt. atrium fails chronic passive congestion lung:
lung hemosiderosis + fibrosis pulmonary hypertension acute pulmonary arteritis (>60 mm)
• Rx: medical; balloon valvuloplasty; surgical repair
preferred; prosthesis, antibiotics
Fishmouth mitral
Mitral stenosis
Normal LV hypertrophy Mitral stenosis
Mitral stenosis
Atrial thrombus
Embolus infarct,kidney
Embolus infarct,spleen
Embolus infarct,brain
Calcified thrombi on mitral valve
Calcified embolus to
coronary artery
CHRONIC RHD: MITRAL STENOSIS (2)
• Lt. atrium fails chronic passive congestion lung:
lung hemosiderosis + fibrosis pulmonary hypertension acute pulmonary arteritis (>60 mm)
• Rx: medical; balloon valvuloplasty; surgical repair
preferred; prosthesis, antibiotics
Mitral stenosis
RVH
PULMONARY CONGESTION
HEMOSIDERIN-FILLED MACROPHAGES
PULMONARY FIBROSIS
Pulmonary arteritis
CHRONIC RHD: MITRAL STENOSIS (2)
• Lt. atrium fails chronic passive congestion lung:
lung hemosiderosis + fibrosis pulmonary hypertension acute pulmonary arteritis (>60 mm)
• Rx: medical; balloon valvuloplasty; surgical repair
preferred; prosthesis, antibiotics
Chordae fused, gone
CHRONIC RHD: MITRAL REGURGITATION
• Rarely “pure” if due to rheumatic fever
• Left heart failure occurs later than in mitral stenosis
• Other causes: ruptured papillary muscle after infarction mitral valve prolapse
AORTIC STENOSIS: CAUSES
• Congenital:
Stenotic at birth
Bicuspid; later calcification
• Rheumatic heart disease
• Atherosclerosis. Rare.
• Idiopathic
“degenerative” calcific aortic stenosis:
most common today in USA
Normal aortic valve
Bicuspid aortic valve stenosis
AORTIC STENOSIS: CAUSES
• Congenital:
Stenotic at birth
Bicuspid; later calcification
• Rheumatic heart disease
• Atherosclerosis.
• Idiopathic “degenerative” calcific aortic
Normal aortic valve
rheumatic aortic stenosis;fused cusps
AORTIC STENOSIS: CAUSES
• Congenital:
Stenotic at birth
Bicuspid; later calcification
• Rheumatic heart disease
• Atherosclerosis. Rare.
• Idiopathic
“degenerative” calcific aortic stenosis:
most common today in USA
Calcific aortic stenosis,etiology?
CHRONIC RHD: AORTIC STENOSIS (1)
• Given amount commissural fusion has more functional impairment of aortic than mitral
• Left Ventricle (pressure and hypertrophy)
• Angina: Systolic coronary artery compression slows or
stops flow in myocardial capillaries. BP in Valsalva sinus (Venturi effect) Valve calcification extends to narrow coronary
artery orifice Coronary atherosclerosis
CHRONIC RHD: AORTIC STENOSIS (2)
• Sudden death Stokes-Adams syncope (arrhythmia? exercise systemic resistance but output fixed by stenosis
• Left failure late but resists Rx. Hence, surgical repair before failure occurs.
• Failure: diastolic filling defect plus systolic contractility are decreased because afterload is increased
symptoms correlate with degree of stenosis
Calcific aortic stenosis, x-ray
AORTIC STENOSIS: Rx
• Medical
• Surgical: Congenital, infant: valvulotomy
Acquired: can’t repair native valve surgically, so use
prosthesis perform before symptoms severe Quantitative CT scan good to assess status
Plastic ball cracked
ball escaped cage aorta
CLOT
CHRONIC RHD: AORTIC REGURGITATION
• RHD infrequent cause (some due to bacterial
endocarditis or aortic dissection)
• Syphilis:
Commissure separation (stretched ring)
Affects ascending aorta most
Mesoaortitis weakens aorta wall aneurysm
Symptoms do not correlate well with degree of
insufficiency
MITRAL VALVE PROLAPSE (1)
• Mitral leaflet bulging into atrium in systole
• Valve leaflets deformed by focal myxomatous
degeneration of valve connective tissue:
Marfan syndrome (fibrillin gene defect)
Chemical change: myxomatous degeneration
in Down syndrome
MITRAL VALVE PROLAPSE
MITRAL VALVE PROLAPSE
MITRAL VALVE PROLAPSE (2)
• Sx: systolic click. May be asymptomatic.
• Dx: Cardiac imaging
• Complications:
Left failure due to mitral regurgitation
Infectious endocarditis
Arrhythmias with sudden death
Embolism from valve thrombi
• Rx: Surgical repair, prosthesis
CHEMICAL CAUSES OF VALVULAR DISEASE
• Fenfluramine, phentermine (fen-phen): Fibrous thickening of all valves Produces pulmonary hypertension
• Carcinoid tumor (serotonin)
• Ergot alkaloids (ergotamine; methysergide) Also pergolide mesylate (used to Rx Parkinson
disease)
• Mechanism of all of above: deposit of fibrous tissue plaque on valve with normal architecture