mitral and tricuspid dz Flashcards
mitral valve anatomy
- annulus
- chordae
- leaflets
- papillary muscle
Mitral valve function
- opens in diastole, allowing blood to flow from the LA to the LV
- closes in systole, preventing blood from flowing backward from the LV to the LA
Mitral stenosis is
decreased mitral valve opening, which causes obstruction of the flow from the LA to the LV during diastole
mitral stenosis leads to
increased pressure within the LA, pulmonary vasculature and right heart
Mitral stenosis: etiology
- rheumatic MS
- calcific MS (3%)
- obstructuve (tumor, like myxoma)
- prosthetic valve (thrombosis, degeneration)
- congeital
acute rheumatic fever
- inflammatory condition involving the heart, skin and c.t.
- complication of URI caused by group a strep
- ARF occurs 2-3 weeks after the initial throat infection
- inflammation of the heart occurs
rheumatic MS
- 80% of MS cases are rheumatic
2. only ~50% of pt report a history of rheumatic fever
ARF symptoms
chills, fever, migraroty arthralgias, fatigue
inflammation of the heart from ARF
- inflammation of valvular endocardium leads to chronic rheumatic heart disease
- symptoms of valve dysfunction typically do not manifest for 10-30 years after initial infection
mitral stenosis: clinical presentation
- dyspnea
- hemoptysis
- pulmonary hypertension
- right sided heart failure
- A fib
- Thromboembolic event
MS dyspnea caused by
↑ in LA pressure → ↑ pulmonary venous capillary pressure → pulmonary edema
MS hemoptysis is caused by
↑ pulmonary vascular pressure → rupture of a bronchial vein into lung parenchyma
MS: right sided HF is due to
see edema and ascities and it is due to RV working chronically against ↑resistance of pulmonary hypertension
MS A-fib is caused by
chronically elevated LA pressure leads to LA dilation
MA thromboembolic event is due to
like a stroke is due to stagnant blood flow in the LA may lead to blood clot formation
Mitral stenosis: cardiac auscultation
- loud S1
- Opening snap
- diastolic rumble
loud S1 is due to
the high AV pressure gradient keeps the MV open until the ventricular systole forcefully closes the valve
the opening snap is due to
the opening snap follows S2 and is due to the opening of the stenotic leaflets
the severity of the MS is inversely proportional to the interval between S2 and OS.
Higher LA pressure forces the valve open earlier
diastolic rumble is due to
low frequency decrescendo murmur due to turbulent flow across the stenosis valve during diastole
the duration but not the intensity correlates with the intensity of the MS
MS: EKG:
- Left atrial enlargement
- RVH if pulmonary hypertension has developed
- atrial fibrillation may be seen
MS: echo
- LA enlargement
- restricted opening of MV during diastole
- thickened mitral valve leaflets, fusion of commissures (rheumatic MS)
MS severity can be estimated by
measuring the pressure gradient with doppler or by direct visualization (planimetry)
MS: grading severity
- mild
- moderate
- severe
by valve area
mean gradient and
PA pressure
mean gradient is
pressure difference between LA and LV during diastole
mild MS ia
> 1.5 valve area
< 30 PA pressure
moderate MS is
1- 1.5 valve area
5-10 mean gradient
30-50 PA pressure
severe MS is
10 mean gradient
> 50 PA pressure
MS treatment
- medications
a. beta blocker to slow HR
b. diuretics to tx CHF symptoms
c. Anti-coag if a-fib is present - mitral valve replacement
MS: Beta blocker tx:
slows HR
slowing HR allows more time for blood to cross the mitral valve in diastole
MS: anti-coag tx
if afib is present
MS can cause stasis of blood flow in the LA, which can lead to thrombus formation and stokre
