28. Mitral Valve Disease Flashcards
(32 cards)
components of the mitral valve?
mitral leaflets, chordae tendinae, papillary muscles
which is more complicated, mitral or semilunar valves?
mitral
the papillary muscles contract when?
during systole
what is the most common disease affecting mitral valve leaflet tissue?
myxomatous degeneration: loose tissue, results in redundancy
what is the result of myxomatous degen?
progressive mitral regurg
how does ischemic heart disease affect the mitral valve?
if there is ischemia/infarct of the LV or papillary muscles, the mitral will malfunction and leak
2 other diseases that can yield a leaky mitral?
infectious endocarditis and connective tissue disease
the majority of mitral stenosis cases are due to what?
rheumatic heart disease
why does rheumatic fever cause rheumatic heart disease?
cross-reactivity: same antibody binds both cardiac muscle sarcolemma and part of the cell wall of the streptococcus.
what is the classic myocardial lesion in acute rheumatic fever?
aschoff body.
what gross pathological changes are seen with chronic rheumatic heart disease?
fibrosis, thickening, shortening, fusion of the leaflets and chordae
what effect does a mitral valve narrowing/stenosis have on the LV?
reduced LV filling, leads to decr SV and CO.
how is the reduced LV filling in mitral stenosis compensated for?
by the LA, which enlarges to produce a diastolic gradient across the valve. causes pulm venous congestion –> HTN, edema, ultimatel right heart failure.
what would be the systemic symptoms associated with mitral stenosis?
- long time of mild dyspnea, then rapid downhill course as mitral valve area decreases.
- dyspnea, orthopnea, fatigue
what cardiac signs would you see/hear with mitral stenosis?
crackles, loud S1, mitral valve opening snap (OS),
with mitral stenosis, what would you see on CXR?
increased LA size, increased RV size. normal LV.
with mitral stenosis, what drug therapy might be suggested?
diltiazem (ca blocker), or metoprolol to slow HR and lengthen diastolic filling time. diuretics for heart failure.
a few causes of mitral valve regurg?
- rheumatic heart disease
- mitral valve prolapse
- ischemia
- infective endocarditis
rheumatic mitral regurg: pathology
fibrous contractures prevent leaflets from closing together. calcification around commissures.
LV hypertrophy and LAE.
rheumatic mitral regurg: pathophysiology
systolic regurg into LA. volume overload of LV. may lead to LV failure, inc pulm pressures.
rheumatic mitral regurg: general clinical findings
heart failure
rheumatic mitral regurg: heart sounds
S1 normal (as opposed to mitral stenosis where S1 is loud). S3 gallop
rheumatic mitral regurg: CXR
LVE, LAE
rheumatic mitral regurg: drug therapy
diuretics, ACE inhbitors, digigalis.
