Mitral prolapse

Question 1

Causes

Answer 1

o Primary: abnormalities of MV leaflets
 CVD
 Secondary/tertiary chord rupture → body of leaflet prolapse into LA
 Endocarditis
o Secondary: w/o pathologic valvular abnormality
 Hemodynamic cause: volume ↓ → ↓LV size
 Myocardial disease → abnormal pap muscle fct + akinetic muscle

Question 2

Features/breeds

Answer 2

• Can be present w/o MR
  o Genetic in CKCS and Dachshund
  o A early as 3y/o, asymptomatic, no murmur
   ↑ incidence of MR later in life

Question 3

Echo findings 2D

Answer 3

• One/both leaflets buckle back in LA during systole
• Apical 4 chamber view
  o Not recommended to assess prolapse of anterior leaflet → normal curving into LA
  o Posterior leaflet buckling into LA always abnormal
• LAE → correlates to severity of dz
  o Except chord rupture

Question 4

2D echo LV fct small dogs

Answer 4

 Acute (chord rupture) or mild MR: normal LVIDd + ↓ LVIDs (↑∑ tone)
 Chronic MR: ↑ LVIDd + LAE α to MR severity
* Normal wall thickness
* Hyperdynamic LV: normal LVIDs and ↑ FS
o Unless myocardial failure

Question 5

2D echo LV fct large dogs

Answer 5

 Valves look less affected
 FS btw 25-40% (vs DCM <15%)
 Commonly hyperdynamic septal wall motion and ↓ free wall motion

Question 6

Doppler echo

Answer 6

o Semi quantitative MR severity evaluation
o Jet velocity = 5-6m/s (correlates to systemic pressure)