Valvular heart disease

VALVULAR HEART DISEASE
Causes
a) stenosis
i) “narrowing” and failure of forward flow
b) insufficiency (regurgitation, incompetence)
i) failure of valve to close completely
- allowing reverse flow
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c) Pure i) stenosis or regurgitation d) mixed i) stenosis and regurgitation coexist in same valve - usually 1 defect predominates e) isolated i) 1 valve f) combined i) more than 1 valve dysfunctional www.freelivedoctor.com

g) flow anomalies through valves produce turbulent flow patterns i) murmurs h) acquired valvular heart disease **ii) students should be able to match various heart valve diseases with both the specific valve involved and whether the disease is a stenosis, regurgitation or both www.freelivedoctor.com

iii) most frequent causes: - AS  calcification of congenitally deformed valve - AI  dilation of ascending aorta (e.g., hypertension and aging) - MS  RHD - MI  mitral valve prolapse (myxomatous degeneration) www.freelivedoctor.com

Calcification
valves subjected to  repetitive
stresses
a) at hinge points of cusps and leaflets
i) 75 bpm x 60 mins = 4500 bph
ii) 4500 bph x 24 hrs = 108,000 bpd
iii) 108,000 bpd x 365 days = ~40 million bpy
iv) 40 million bpy x 75 yrs = 3 billion bp your life !

b) deformations during each beat c) pressures on valves in closed phase i) 120 mmHg  mitral valve ii) 80 mmHg  aortic valve d) the factors listed above (a,b,c) contribute to valvular damage seen by calcium deposits (Calcium Phosphate) i) 1 0 dystrophic calcification (different from atherosclerosis) - calcific AS - mitral annular calcification www.freelivedoctor.com

Calcific Aortic Stenosis
a) most common of all valvular abnormalities
i) geriatric (“wear and tear”)
of normal valve or congenital bicuspid aortic valve
b) incidence  due to  age
c)  incidence of RF in No. America
i) < 10% of acquired stenosis
d) 6-7 th decades (bicuspid valve)
e) 8-9 th decades (normal valve)
i) “senile calcific aortic stenosis”

f) Clinical: i) LV outflow obstruction - LV compensates by  LVP to ~ 200 Hg  develops - LV concentric hypertrophy (pressure overload !!): CHF - ischemic myocardium  - angina may appear - systolic and diastolic impairment (e.g., syncope) ii) the S & S above indicate decompensation (poor progno.) www.freelivedoctor.com

g) 50% die within 5 yrs with angina
h ) 50% die within 2 years with CHF
i) patients w/out symptoms have excellent outcome
i) symptoms are critical factors
in management and outcome !!
Calcific stenosis of Congenitally
Bicuspid Aortic Valve
a) frequency ~ 1.5% live births
b) NOT symptomatic at birth or
through early life
c) 2 leaflets. 1 is larger

i) larger leaflet increases calcification ii) once stenosis occurs, progression is similar to normal aortic valve d) bicuspid aortic valves may be acquired (RHD)  fused leaflets e) other causes of bicuspid aortic valve incompetence i) aortic dilation ii) cusp prolapse iii) infective endocarditis www.freelivedoctor.com

A . Acquired bicuspid aortic valve with secondary calcification. At the center of the conjoined cusp (lower center) are elements of two preexisting cusps, now fused. B. Congenital bicuspid valve. The characteristic raphe of the congenital bicuspid aortic valve appears at the lower portion of the figure. C. Senile type. None of the commissures is fused, but there is a major intrinsic calcification of the three cusps. D. Unicuspid, unicommissural congenital aortic stenosis with secondary calcification. A B C D www.freelivedoctor.com

Calcific aortic stenosis occurring on a congenitally bicuspid valve. One cusp has a partial fusion at its center, called a raphe (arrow). www.freelivedoctor.com

Mitral Annular Calcification
a) calcific nodules arounf fibrous annular ring of mitral valve
b) usually does not affect valvular function
i) rare cases:
- stenosis
- regurgitation
- sudden death (Ca ++ dependent)
- thrombus formation (stroke) and infections

c) women > 60 yrs,  LVP, mitral valve prolapse, hypertrophic cardiomyopathy
Myxomatous Degeneration of Mitral
Valve (Mitral Valve Prolapse)
ballooning back during systole
one of most common valvular heart
diseases
a)  incidence in women
b) usually presents as incidental finding on physical exam

c) affected leaflets are thickened i) due to mucoid deposits (“ Myxomatous ”) ii) cords are usually elongated thinned and often ruptured iii) annular dilation characteristic - leaflets balloon - rare in other mitral insufficiencies iv) thrombi formation - behind ballooned cusps (on leaflets) www.freelivedoctor.com

d) clinical: i) most asymptomatic - midsystolic “click” ii) ~3 % develop complications: - infective endocarditis - mitral insufficiency (requiring surgery) - stroke - arrhythmias (atria & ventricular - - “sudden death”) iii) if complications  surgery www.freelivedoctor.com

Rheumatic Fever and Heart Disease
RF is acute inflammation
a) within weeks following group A streptococcal pharyngitis
i) cross reaction of Ab directed at M proteins of Strep. proteins with glycoprotein Ag in heart, etc.
b) acute carditis (RF) may develop to chronic RHD

c) consequence of RF is chronic valvular deformities (fibrosis) i) mitral and aortic - mainly mitral stenosis - permanent www.freelivedoctor.com

Pathology :
a) RF  focal inflammatory lesions
i) “Aschoff” bodies
- swollen eosinophilic collegen
- found is any layer of the heart (“pancarditis”
- in pericardium  fibrinous or serofibrinous exudate
ii) “Anitschkow” cells
- swollen macrophages and/or plasma cells

b) RHD – chronic i) organized acute inflammation - fibrosis  ii) leaflet thickening iii) commissure fusion (stenosis) - “buttonhole” or “fishmouth” stenoses iv) cord fusion / thickening v) Aschoff bodies replaced with fibrous scar www.freelivedoctor.com

Stenotic mitral Valve seen from left atrium. Both commissures are fused; the cusps Are severely thickened.The left atrium is huge. The valve is both incompetent and stenotic www.freelivedoctor.com

Opened stenotic mitral valve showing thickening distorted cusps, adherent commissures with calcification and thrombus deposition, and thickening, fusion and shortening of chordae tendinae www.freelivedoctor.com

vi) major cause of mitral stenosis - ~ 99% - mitral valve alone ~ 70% - mitral / aortic valve ~ 25% c) etiology unknown i) believed to result from connective tissue defects -  in Marfan Syndrome www.freelivedoctor.com

Clinical:
a) migratory polyarthritis
i) large joints
b) carditis
c) s.c. nodules
d) erythema marginatum
e) Chorea movements (CNS)
(Sydenham Chorea)
(“St. Vitus Dance”)

s.c. nodule   www.freelivedoctor.com

Infective Endocarditis
Most cases are bacterial
Classification based on clinical grounds
a) acute
i) destructive (necrotic, ulcerative) valvular infections
ii) highly virulent
iii) frequently of healthy valve
iv) ~ 50% lethal: days to weeks
- despite antibiotics/surgery

b) Subacute
i) low virulence
ii)  recovery with antibiotic Tx
iii) vegetative growths show signs of healing
Etiology and Pathogenesis
a) may develop on normal valves
b) most develop as result of:
i) RHD
ii) myxomatous mitral valve
- most common today

iii) other factors - calcific stenosis - prosthetic valves - bicuspid aortic valve - immunodeficiency - neutropenia - diabetes - alcohol c) causative organisms i) Strep viridans (50-60%) - previously damaged native valve www.freelivedoctor.com

ii) Staph aureus (10-20%) - found on skin -  virulence - attack normal or damaged valves - i.v. drug users !! iii) HACEK group - H aemophilus - A ctinobacillus - C ardiobacterium - E ikenella - K ingella www.freelivedoctor.com

iv) Prosthetic valves
- Staph epidermidis
- Staph aureus
v) gram (-) bacilli and fungi
Seeding of blood with microbes main
cause
a) dental or surgical procedures, etc
Aortic and mitral valves most common
a) right sided valves in i.v. drug abusers
Clinical:
a) rapid fever (acute IE)

i) chills ii) weakness iv) immune mediated GN v) murmurs (~90%) - left side lesions b) subacute (mild or absent T o ) - fatigue - flu-like symptoms - weight loss www.freelivedoctor.com

www.freelivedoctor.com Common Manifestations of Infective Endocarditis . Splinter hemorrhages (Panel A) are normally seen under the fingernails. Panel B shows conjunctival petechiae. Osler's nodes (Panel C) are tender, subcutaneous nodules, often in the pulp of the digits or the thenar eminence. Janeway's lesions (Panel D) are nontender, erythematous, hemorrhagic, or pustular lesions, often on the palms or soles.

Non Infective Endocarditis
Nonbacterial Thrombotic Endocarditis
(NBTE)
a) sterile, nondestructive
b) small masses of fibrin, platelets, etc.
i) on leaflets of cardiac valves
c) often seen in debilitated pts
i) cancer
d) may produce emboli
i) stroke in brain, heart, etc.

e) frequently occur with DVT and PE i) common origin with hypercoagulable states - may be related to some underlying disease, such as pancreatic cancer, leukemia, burns and sepsis, DIC - indwelling catheters (SG) induce right valve lesions www.freelivedoctor.com

Libman-Sacks Disease
a) associated with the autoimmune disease SLE
i) mitral and aortic valves
- mitral more common
- underneath valves
- on cords
b) sterile vegetations
c) regurgitation

Carcinoid Heart Disease
a) associated with systemic syndrome caused by carcinoid tumors
i) ~ 50% of patients with carcinoid syndrome
- flushing of skin
- cramps
- vomitting
- diarrhea
i) endocardium
ii) valves of right heart (~90%)
b) serotonin correlate with severity

Valvular heart disease

by raj kumar on Apr 16, 2010

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Valvular heart disease — Presentation Transcript

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