PV assessment

Question 1

Types of obstruction PV

Answer 1

o Subvalvular constriction may occur by itself or in conjunction w valvular
 Fibrous ring at base of valve → fibromuscular narrowing of infundibular region
 Excessive concentric infundibular of supraventricular crest hypertrophy → can cause dynamic obstruction
 Can be associated with CA anomaly (see below)
o Supravalvular is rare → narrowing of PA
 Can also invole branches of PA → rare

Question 2

Type I (A) PS echo features

Answer 2

 Commissural fusion
* Valve doming toward PA
* Fused semilunar cusps do not separate completely
 Restricted movement → ↓ body of valvulae curve toward PA wall during systole
 Little if any thickening
 Normal annular size: Ao/PV <1.2
 Post stenotic dilation

Question 3

Type II (B) PS echo features

Answer 3

 Valvular dysplasia present → cusps are thickened and immobile
* No commissural fusion
 Hypoplasia of annulus, cusp, PA
* Ao/PV ratio >1.5
 Subvalvular ring can be present

Question 4

Breeds high prevalence of PS

Answer 4

• Bull mastiff
• Beagle
• Bulldog → English bulldogs reported as most common breed
• Boxer
• Keeshond
• Schnauzer
• Chihuahua

Question 5

General echo features of PS

Answer 5

o RVH → concentric hypertrophy of RVFW and IVS
 ↑ afterload from obstruction to flow

o Abnormal PV leaflets and OT

o Post stenotic dilation of PA → beyond valves
 Degree of dilation do not correlate w severity of obst.

o ± RAE/RVE
* RA dilation: reported in cats/dogs w PS
o Diastolic/systolic dysfct of abnormal RV
o Concurrent TV dysplasia and 2nd TR
o 50% of dogs have some degree of TR
 Associated with worse px

• Paradoxical IVS motion: exaggerated displacement toward LV in systole
  o 2nd to ↑ RVP → ↓ PG btwn ventricles
• Left side: pseudo hypertrophy
  o ↓ pulmonary venous return

Question 6

Assess PV/PA

Answer 6

o Valvular thickening, leaflet fusion and mobility
o Fixed sub/supravalvular obstruction

• Hypoplastic PA: compare PA diameter to Ao diameter
  o Ratio PA/Ao = 0.8 to 1.15 in normal dogs

Question 7

Views to assess PV

Answer 7

R SAX transverse and oblique, LCr LAX, L transverse

Question 8

Coronary arteries assessment

Answer 8

o Bulldog, boxer may have abnormal CAs
 R2A anomaly
o Right single CA → divide shortly after leaving R coronary ostium
 1 branch supply RV
 Other supply LV → aberrant pathway
* Cranial to PA
* Btwn PA and Ao
* Caudal to Ao
 Aberrant CA may constric t PV annulus/subvalvular area and create stenosis
o Identification of LCA important → risk of rupture during balloon valvuloplasty if single RCA
 On R SAX basilar view at jct of LA appendage and PA

Question 9

Spectral Doppler evaluation PS

Answer 9

• Normal PA flow < 1.3m/s
• PW gate: help determine level of obstruction
  o Then switch to CW to assess severity of obstruction
   Max and mean PG through stenosis
  o Gradient severity = same as SAS
   Mild 25-50mmHg, moderate 50-80mmHg, severe >80mmHg
• Dynamic RVOTO can occur → dagger shaped flow profile
• Diastolic antegrade flow → graded based on how long it persists

Question 10

Color flow Doppler PS

Answer 10

o Assess width of OT and valvular orifice
o Usually overestimate size of stenotic area
o Use to assess concomitant ASD, VSDs