ECHO 3 : Valvular Stenosis

what can cause valvular stenosis?

• congenitall abnormal valve

• post inflammatory

• age related

which valve does rheumatic disease affect first?

mitral

valvular stenosis results in

pressure overload

what is the ventricular vs atrial responsce to pressure overload?

ventricular → hypertrophy

atrial → dilatation 

how does a narrowed orifice affect velocity?

smaller the opening, the greater the velocity of the jet

what occurs as a result of aortic stenosis?

concentric left ventricular hypertrophy

(LV must generate higher pressure to move blood through. It does this by thickening muscular walls EQUALLY aka concentric) 

what are the symptoms of severe AS?

fatigue

decreased exercise tolerance

chest pain 

difficulty breathing on exertion

aortic sclerosis is common in

adults older than 65 (25% have it)

what is ao sclerosis?

focal areas of increased echogenicity without significant obstruction

in ao stenosis what kind of data is recommended to provide functional valve area

doppler data 

what accounts for most cases of severe AS in adults younger than 70?

bicuspid aortic valve (accounts for 2/3 of those cases)

what is raphes?

lines present where the valve does not open (typically in larger leaflet) so when closed valve looks trileaflet

should bicuspid ao valve be diagnosed in diastole or systole?

systole because in diastole when it is closed the raphe may make it appear trileaflet

what does a bicuspid valve look like in PSAX?

in systole only 2 leaflets “open”

what does bicuspid ao valve appear like on m mode? **

eccentric line closure

bicuspid AO valve is associated with

dilatation of aortic sinuses and ascending aorta

coarctation of aorta

aneurysm

aortic dissection

what is the most comon bicuspid AV valve

larger anterior leaflet with opening along anterolateral posterior closure line

what does rheumatic aortic stenosis typically present with

increased echogenicity along leaflet edges

commisural fusion

systolic doming of aortic leaflets 

rheumatic disease is more likely when ao disease occurs

concurrently with typical rheumatic mitral changes 

when does rheumatic heart disease occur?

typically starts in childhood acutely and is followed by lifelong progressive valvular damage 

bicuspid ao valve is what type of stenosis?

congenital

what are differential diagnosis for aortic stenosis? *

fixed subvalvular obstruction (subaortic membrane or muscular subaortic stenosis)

dynamic subaortic obstruction (hypertrophic cardiomyopathy)

supravalvular stenosis

what causes ao stenosis?

degenerative calcific aortic stenosis (elderly >70)

bicuspid aortic stenosis (young/middle aged)

rheumatic aortic stenosis (young/middle aged)

what are the main measurements to quantify severity of ao stenosis?

max ao jet velocity

mean transao pressure gradient 

continuity equation valve area

what doppler is used to measure ao stenosis?

CW bc of high velocities (3-6m/s)

how is mean transo pressure gradient calculated?

by tracing the velocity curve and avering instantaneous gradients over systolic ejection period

how is the continuity equation measured for ao stenosis?

LVOT

LVOT VTI

AO jet VTI 

why is LVOT measurement important in continuity equation?

to calc CSA(LVOT) you need to square LVOT so small differences in diameter measurements can make significant differences in area calculations

why is pedoff probe used in ao stenosis? what views?

smaller footprint and better sensitivity for doppler

• apical 5CH

• suprasternal

• right parasternal

what are potential pitfalls in measuring ao stenosis?

poor doppler beam alignment

inaccurate LVOT dimension

beat to beat variability (AF,PVCs)

grading for AS severity

what are additional measurements used for ao stenosis?

planimetry

ao cusp separation

what is planimetry in ao stenosis?

tracing ao valve border to get an area

what planimetry measurement should raise concern for ao stenosis?

<2cm²

what cusp separation measurement should raise suspicious for ao stenosis?

</= 1.5cm

why is velocity ratio used in ao stenosis? (dont focus on)

to reduce error from LVOT diameter by removing CSA from continuity equation (Vlvot / Vav)

smaller velocity ratio indicates

stenosis

(closer to 1 → absence of valve stenosis) 

what will you see with low flow aortic stenosis? (dont focus on)

ao velocity less than 4 m/s

valve area less than 1cm

presence of LV dysfunction less than 50% (reduced EF)

how is low flow ao stenosis evaluated? (dont focus on)

degree of valve calcification 

dobutamine stress echo

what is a subaortic stenosis?

fixed stenosis and considered NON VALVULAR (valve could be completely normal)

hockey stick valve appearance is specific to**

mitral valve

what is used to evaluate severity of mitral stenosis?

3d/2d planimetry

mean gradient

pressure half time

rheumatic disease almost always affects - and nearly always the cause of -

mitral valve

mitral stenosis

mitral stenosis is characterized by

commisural fusion → bowing or doming of leaflets in diastole → hockey stick appearance of AMVL

what do you need to evaluate as a result of mitral vavle obstruction?

LA size

LA thrombus

estimate pulmonary pressures

RV size and systolic function 

how does mitral annular calcification affect stenosis?

calcific stenosis rare in mitral valve

what does this represent?

planimetry of MV in diastole 

in what window are pressure gradients measured?

apical window

how is pressure gradient measured in mitral valve stenosis?**

CW/PW of mitral inflow through mitral leaflets and then trace

how does the analysis package calcualte pressure gradients?

averages the instantaneous gradients over the diastolic filling period suing bernoulli equation 

what is the range for mild, moderate, and severe stenosis with regarding mean gradients of mitral valve?**

mild : <5mmHg

moderate : 5-10mmHg

severe : >10mmHg

what is pressure half time? and how is it measured?**

time it takes for pressure to go down by half 

trace waveform 

what is considered severe pressure half time for mitral stenosis? mild?

severe : >220

mild : 100

what are common reasons for an increase in pressure gradients across  mitral valve?

DOE (dyspnea on exertion) 

conditions that increase cardiac output

tachycardia (shortens diastole → interferes with LA emptying)

what is the pressure half time formula?

MVA = 220/PHT

how is PASP measured?

TR jet + RAP estimation

what is normal IVC measurement 

2.1 

how do we calculate RAP?

normal IVC size and collapses 50%+ = 3

dilated IVC size and does not collapse 50%+ = 15 

everything else = 8 

what is parachute mitral valve

cause of stenosis 

both valves attached to the same pap muscle 

what is a secondary measurement for evaluate mitral stenosis?

MVA continuity equation : CSA (mv) = [CSA(lvot) x VTI(lvot)] / VTI(mv) 

what is a myxoma?

non rheumatic form of mitral stenosis where tumor prolapses into mitral valve funnel in diastole and produces inflow obstruction 

what is characteristic finding in mitral stenosis m mode?

decreased E/F slope

mitral annular calcification (MAC) is most commonly observed in which leaflet?

posterior leaflet 

what is very commonly seen in MAC?

calcium deposits

large mitral calcifications can produce

moderate to severe mitral regurg (rarely stenosis)

how does calcification compare in MAC vs rheumatic mitral stenosis?

MAC : calcification at the basal portion of leaflets

rheumatic mitral stenosis : tips/free edges are thickest portion of the leaflets

severe MV pressure half time

>/= to 220 msec 

normal MV pressure half time

<60 msec 

what is normal mitral valve area?

4-6cm²

what is considered severe MV area?

<1cm²

mitral stenosis severity scales

tricuspid valve stenosis is usually due to

rhuematic tricuspid valve involvement in patients with mitral stenossi

pulmonic stenosis is usually caused by

congenital heart disease

review qs

what is the most common cause of ao stenosis?

age related calcification

review qs

what is the most common cause of congenital ao stenosis?

bicuspid ao valve

review qs

what is bicuspid ao valve associated with

dilatation of ao

coarctation 

aneurysm 

ao dissection 

review q

how do we assess ao stenosis?

max velocity

mean pressure gradient 

continuity equation 

review qs

what is the most common cause of mitral stenosis? other causes?

rheumatic fever

age related, tumor 

review qs

what valve does rheumatic fever affect first?

mv → ao → tv

review qs 

what are the two ways to assess mitral stenosis and MVA? which is most accurate?

mean pressure gradient (most accurate) 

pressure half time (PHT ) 

planimetry