Valvular disorders Flashcards
(47 cards)
What are the four valves in the heart and what is their function?
tricuspid, pulmonary, mitral, and aortic that prevent
back flow.
What is the general effect of valvular lesions?
Valvular lesions generally result in stenosis (decreased caliber of the valve orifice) or regurgitation (backflow).
What is Rheumatic Fever?
Rheumatic fever (RF) is an illness which arises as a complication of untreated or inadequately treated strep throat infection. Rheumatic fever can seriously damage the valves of the heart.
What complication leads to acute rheumatic fever?
Systemic complication of pharyngitis due to group A [5-hemolytic streptococci; affects children 2 - 3 weeks after an episode of streptococcal pharyngitis (“strep
throat”)
What causes Acute rheumatic fever?
Caused by molecular mimicry; bacterial M protein resembles proteins in human tissue.
How is Acute Rheumatic fever diagnosed?
Diagnosis is based on Jones criteria.
What is jones criteria?
- Evidence of prior group A |5-hemolytic streptococcal infection (e.g., elevated ASO or anti-DNase B titers) with the presence of major and minor criteria
- Minor criteria are nonspecific and include fever and elevated ESR.
- Major criteria
What are the major criterias in jones criteria?
- Migratory polyarthritis
- Pancarditis
3-Subcutaneous nodules
4. Erythema marginatum
5.Sydenham chorea
What is Migratory polyarthritis?
swelling and pain in a large joint (e.g., wrist, knees, ankles) that resolves within days and “migrates” to involve another large joint
What is pancarditis?
diffuse inflammation of the heart
- *a. Endocarditis**—Mitral valve is involved more commonly than the aortic valve. Characterized by small vegetations along lines of closure that lead to regurgitation
- *b. Myocarditis** with Aschotf bodies that are characterized by foci of chronic inflammation, reactive histiocytes with slender, wavy nuclei (Anitschkow cells), giant cells, and fibrinoid material; myocarditis is the most common cause of death during the acute phase.
- *c. Pericarditis**—leads to friction rub and chest pain
What is Erythema marginatum?
annular, nonpruritic rash with erythematous borders, commonly involving trunk and limbs
What is Sydenham chorea?
rapid, involuntary muscle movements
What is the complication of acute rheumatic fever?
Acute attack usually resolves, but may progress to chronic rheumatic heart disease; repeat exposure to group A -hemolytic streptococci results in relapse ol the acute phase and increases risk for chronic disease
What is the consequence of rheumatic fever in chronic rheumatic heart disease?
Valve scarring that arises as a consequence of rheumatic fever
What is the most common structures affected in Chronic Rheumatic Fever?
Almost always involves the mitral valve; leads to thickening of chordae tendineae and cusps
What is the hearts usual appearance in Chronic rheumatic fever?
Results in stenosis with a classic ‘fish mouth’ appearance
What is the second most common valve affected in chronic rheumatic heart disease?
Occasionally involves the aortic valve; leads to fusion of the commissures
What is the main complication in chronic rheumatic heart disease?
Complications include infectious endocarditis.
What is Aortic Stenosis?
Narrowing of the aortic valve orifice
What is the usual cause of aortic stenosis?
Usually due to fibrosis and calcification from “wear and tear”
At what age does Aortic stenosi usually occur?
Presents in late adulthood (> 60 years)
What valve disorderincreases risk and hastens aortic stenosis?
Bicuspid aortic valve increases risk and hastens disease onset. A normal aortic valve has three cusps; fewer cusps results in increased “wear and tear” on each cusp.
Can chronic rheumatic valve disease cause aortic stenosis?
May also arise as a consequence of chronic rheumatic valve disease; coexisting mitral stenosis and fusion of the aortic valve commissures distinguish rheumatic
disease from “wear and tear.”
What sound is heard in aortic stenosis and when?
Cardiac compensation leads to a prolonged asymptomatic stage during which a systolic ejection click followed by a crescendo-decrescendo murmur is heard.
