valvular heart disease arthur c. aufderheide, m.d. med 6655. cardiovascular system

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