Mitral stenosis

Question 1

Features

Answer 1

Rare

Question 2

Breeds w/ incr incidence

Answer 2

Newfoundland and Bull Terrier

Question 3

Concomitant congenital defects

Answer 3

SAS, PDA, VSD, endocardial fibroelastosis, coarctation of Ao

Question 4

Echo M-Mode findings

Answer 4

o // motion of anterior + posterior valve leaflets (concordant motion)
 Diagnostic of MV stenosis
o Prolonged MV EF slope

Question 5

2D echo findings

Answer 5

o LAE → from restriction of LV filling
o Thick MV leaflets
o Doming of MV leaflets → cusp fusion
 Tips of leaflets points toward each other at maximal opening
o ↓ diastolic excursion of either or both leaflets
o +/- supravalvular ring
o Normal MV area in dogs: 3.69+/- 1.42cm2

Question 6

Doppler color findings

Answer 6

o Narrow MV orifice 2nd to commissural fusion
o Aliased color flow jet flowing into LV in diastole
 ↑ velocity and turbulence
 Peak velocity usually >1.1m/s

Question 7

Doppler spectral findings

Answer 7

o Mitral inflow pattern
 Reflect PG across MV
* Mean PG calculated from tracing mitral inflow pattern borders
* Reported 1.4-2.5m/s (8-25mmHg)
 Prolonged early diastolic slope (E wave deceleration time)
* Normally: LVP ↑ while LAP ↓ in early diastole
* Rapid decrease in E slope since rapid pressure equalization
 Measure of slope → pressure ½ time calculation
* Time required for pressure to ↓ to ½ its value
* Follow outline of E to F slope, A wave should be ignored
o MV area = 220/P½
* ↑ pressure ½ time
o The longer = more severe stenosis
o Affected by: AI → ↑LVP more rapidly → ↓ pressure ½ time
* Normal: dog = 29 +/- 8ms (<50ms), cats <30ms
o MR: higher PG vs animals with same valvular area