Valvular heart disease Flashcards
Cardiac valves
Maintain unidirectional flow of blood
Lined by endothelium
Semi lunar valves- Aortic and pulmonary
AV valves- mitral and tricuspid (free margins attached to ventricular wall via chordae tendinae and papillary muscles
Valvular heart disease
Stenosis- failure of a valve to open completely (usually a chronic process affecting a valve cusp)
Insufficiency: failure of a valve to close completely (functional regurgitation-valvular incompetence due to disruption of supporting structures, Aorta root dilation and LV dilation, Intrinsic disease of Valve cusps
Cause of valvular disease major cause
Congenital causes (bicuspid aortic valve), Acquired causes (aortic valve stenosis (senile calcific), Insufficiency (ilation of ascending aorta related to HTN and age)
Mital valve Stenosis: Rheumatic heart disease, Insufficiency: Myxomatous degeneration
Stenosis»> insufficiences
Calcific Valvular Disease
Dystrophic calcification: damage caused by wear and tear complicated by deposits of calcium phosphate
distinct from atherosclerosis, but shares some risk factors (hyperlipidemia, hypertension, inflammation)
Calcific aortic stenosis
Most common of all valvular abnormalities
Occurence: 5os 60s - bicuspid, unicspid valve (notch mutation, 890s normal valves senile
Clical effects: LV: increased pressure causes Hypertrophy
Angina, ischemia and CHF, syncope,
Treatment valve replacement
Heaped up calcified masses in cusps, primarily at the bases, free cuspal edges not involved, no fusion of commisures
Mitral annular calcification
Degenerative calcific deposists on fibrous ring, at base of valve
Women> 60 Yrs old
increased in patients with myxomatous valves or elevated LV pressure
Usually doesnt affect valve function but site of thrombi/infection
Myxomatous degeneration of mitral valve (prolapse)
very common, young women, usually not serious
One or both leaflets enlarged, hooded redundant floppy
Prolapse or balloon back into left atrium during systole
Pathogenesis unknown: developmental anomaly of CT, marfan syndrome
Clinical features/complication: asymptomatic, regurgitation (late systolic/holosystolic murmur) Complications uncommon (IE, Mitral insuf, thrombi on atrial surfaces, arrhythmias-> sudden death
Rheymatic fever and heart disease
Acute, im mune mediated, multisystem, inflammatory disease
Occurs after group A strep (pyogenes) pharyngitis
Most important complciation: progresion to chronic valvular dysfunction (mitral stenosis)a\
Acute rheumatic fever morphology
widely disseminated inflammatory lesion found in many sites
Pancarditis (affects all three layers)-pericarditis, myocarditis with aschoff bodies, endocardium and left sided valves with fibrinoid necrosis and verrucae, subendocardial Maccallum plaques: irregular fibrous theckening of endocardium
Classic lesion is Aschoff body (foci of swollen eosinophillic collagen surrounded by Tcell, plasma cells and plump Macrophages- Anitschkow cells, caterpillar cells
Chronic rheumatic heart disease
inflammation and fibrosis leads to thickened valve leaflets, fusion of commissures (fishmouth or buttonhole deformaties), fusion/thickening of chordae tendinaee
Major effect is mitral stenosis– left atrial dilatation (thrombus) reduced cardiac output, pulmonary congestion eventual right ventricular hypertrophy and right sided heart failure
Pathogenesis: HS reaction induced by group A Streptococci, antibodies against M protein cross react with gcp Ag in the heart joints and other tissues
JONES
Preceding group A strep infection and 2 major manifestaion (or 1 maj and 2 min)
Major: migratory polyartheritis, carditis, Nodules, Erythema marfinatum, Synednham chorea
Minor: Fever, arthralfia, elevated acute phase reactants
Clinical features and course: ASO tites
Inefective endocarditis
Acute: highly virulent organism, normal valve, mortality, necrotizing ulcerative invasive infection
Subacute: low virulence, deformed valve, less destructive lesions, respond to antibiotics
Etiology/pathogenesis: CV abnormalities, host factors
Strep viridans 50-60%
S aureus organism in
