1. Ventricular Septal Defects
Echo Conference 5/11/11
Darryn Appleton

2. Outline Morphology, Types & Pathophysiology
Natural History and Clinical Presentation
Some Echo examples
Clinical Scenarios and Recommendations
Interventions: Indications, Surgery, Percutaneous
Pregnancy and Endocarditis Prophylaxis
Review Questions

3. Introduction
The most common form of CHD, accounting for up to 20-40% of patients diagnosed with CHD
Impact may range from asymptomatic to pulmonary HTN, LV volume overload and RVH
Morphology: 4 types
Membranous – most common type in adults (80%)
Muscular – most common type in young children
Complete AV septal (endocardial cushion) defects
Supracristal (subarterial)

4. Morphology – The Ventricular Septum

5. Morphology – The Ventricular Septum
Membranous
Outflow
Trabecular septum
Inflow
Subarterial / Supracristal

6. VSD Types

7. VSD Types

8. VSD Types

9. Pathophysiology Defect size is often compared to aortic annulus
Large: > 50% of annulus size
Medium: 25-50% of annulus size
Small: <25% of annulus size

10. Pathophysiology
Restrictive VSD is typically small, such that a significant pressure gradient exists between the LV and RV (high velocity), with small shunt (Qp/Qs ≤ 1.4 : 1)
Moderately restrictive VSD  moderate shunt (Qp/Qs 1.4 to 2.2 : 1)
Large / non-restrictive VSD  large shunt (Qp/Qs > 2.2 : 1)
Eisenmenger VSD  irreversible pulmonary HTN and shunt may be zero or reversed (i.e. RL)

11. Natural History
Restrictive: typically does not have hemodynamic impact and may close spontaneously
Location Location Location: Subaortic may result in progressive AI
Moderately restrictive: does create LV overload and dysfunction along with variable increase in PVR
Large / non-restrictive: LV volume overload earlier in life with progressive pulm HTN and ultimately Eisenmenger syndrome

12. Clinical Features Peds: Adults: Murmur Dyspnea, CHF, Failure to thrive
Asymptomatic murmur – harsh, pansystolic, left sternal border
Mod restrictive – dyspnea, a.fib, displaced apex, murmur, S3
Non-restrictive Eisenmenger VSD – central cyanosis, clubbing, RV heave, loud P2

13. Echo Example 1

14. Echo Example 1

15. t
Outlet VSD – Para long axis

16. Echo Example 2

17. Echo Example 2

18. Echo Example 2

19. Supracristal VSD, with pulm outflow tract obstruction

20. Echo Example 3

21. Echo Example 3

22. Echo Example 3

23. Echo Example 3

24. Echo Example 3

25. Echo Example 3
Type:
Size:
Membranous
Restrictive

26. Echo Example 4

27. Echo Example 4

28. Echo Example 3 Type: Size: Shunt: Muscular Large / Non-restrictive
RL (inc RH pressures)
RV dilated
Eisenmengers

29. Clinical Scenarios & Recommendations
Symptomatic young infant with Pulm HTN
Early surgery within 3 months.
Medical therapy with diuretics +/- ACEI pre-op
Asymptomatic pt without Pulm HTN but with LV overload
Closure usually recommended to avoid late LV dysfunction
Asymptomatic pt, small VSD, no LV dilation
Conservative
Asymptomatic pt, small VSD but with AI/prolapse
Peri-membranous VSD with more than trivial AI should have surgery

30. Clinical Scenarios & Recommendations
Eisenmenger Syndrome
Supportive
Bosentan (Endothelin receptor antagonist) – improves functional capacity, QOL
Sildenafil
Penny DJ, Vick GW. Lancet 2011; 377:

31. Interventions Indications for Surgical Closure in adults:
Evidence of LV volume overload (Class I if Qp/Qs >2, Class IIa if Qp/Qs > 1.5)
History of bacterial endocarditis (Class I)
Significant LR shunt with PA pressure < 2/3 systemic and PVR is < 2/3 SVR
Surgical Closure
Considered the first-line choice of therapy for those with indications
Usually involves direct patch closure w cardio-pulm bypass
Operative mortality < 2% in most centers

32. Long Term Surgical Outcomes
Retrospective review of 46 pts with surgical VSD repair at Mayo Clinic
Mongeon et al. JACC Int 2010; 3: 290-7

33. Interventional Options
Percutaneous Device Closure
Muscular VSDs can typically be closed percutaneously
Class IIb recommendation in Guidelines (i.e. surgery still preferred)
No FDA approved devices for perimembranous VSDs, although there are specific devices for this purpose
Concern re proximity of defect to AV node and high risk of complete AV block requiring pacemaker

34. Pregnancy and VSDs
Pregnancy well tolerated in women with small to moderate sized VSDs as long as there is no pulmonary vascular involvement
Eisenmenger syndrome: Pregnancy contraindicated due to exceptionally high risk of maternal and fetal death

35. Endocarditis Prophylaxis for VSD
Uncomplicated VSD – no Abx for dental or other procedures required
Post repair:
Abx for 6 months following surgical or percutaneous repair
Indefinite Abx if there is residual shunt
Risk of bacteremia from daily life usually exceeds that of procedure  Abx for procedures only prevent small % of cases
Focus should be on optimal dental hygiene for those with CHD

36. Question 1
An isolated VSD will generally cause enlargement of which chamber(s):
A: Left atrium, left ventricle
B: Right ventricle
C: Right ventricle, pulmonary artery
D: Aorta
E: Right ventricle, right atrium

37. Question 1
An isolated VSD will generally cause enlargement of which chamber(s):
A: Left atrium, left ventricle
B: Right ventricle
C: Right ventricle, pulmonary artery
D: Aorta
E: Right ventricle, right atrium

38. Question 2

39. Question 2 The defect shown on the previous slide is a:
A: Muscular VSD
B: Sinus venosus VSD
C: Perimembranous VSD
D: Inlet VSD
E: Supracristal VSD

40. Question 2 The defect shown on the previous slide is a:
A: Muscular VSD
B: Sinus venosus VSD
C: Perimembranous VSD
D: Inlet VSD
E: Supracristal VSD

41. Question 3 A common complication of this defect is:
A: Pulmonary valve endocarditis
B: Aortic regurgitation
C: Aortic dissection
D: Tricuspid regurgitation
E: Right ventricular enlargement

42. Question 3 A common complication of this defect is:
A: Pulmonary valve endocarditis
B: Aortic regurgitation
C: Aortic dissection
D: Tricuspid regurgitation
E: Right ventricular enlargement

43. Question 4 There is no diastolic flow in this perimembranous VSD
A: True
B: False

44. Question 4 There is no diastolic flow in this perimembranous VSD
A: True
B: False

45. Question 5
A restrictive VSD is a simple lesion with a good long term prognosis. However, complications can occur. All of the following are possible complications of a VSD except:
A: Endocarditis
B: Aortic regurgitation
C: Aortic valve prolapse
D: Eisenmenger Syndrome
E: Right sided volume overload

46. Question 5
A restrictive VSD is a simple lesion with a good long term prognosis. However, complications can occur. All of the following are possible complications of a VSD except:
A: Endocarditis
B: Aortic regurgitation
C: Aortic valve prolapse
D: Eisenmenger Syndrome
E: Right sided volume overload

47. Question 6

48. Question 6
The pulmonary artery systolic pressure in this patient with a VSD is:
A: Normal
B: Moderately elevated
C: Systemic / Supra-systemic

49. Question 6
The pulmonary artery systolic pressure in this patient with a VSD is:
A: Normal
B: Moderately elevated
C: Systemic / Supra-systemic

50. Question 7
A patient with a VSD undergoes TTE. BP measured at the time of the study is 125/75 (right arm), MAP 92. CW doppler across the VSD gives a peak velocity of 5 m/s. Assuming RA pressure of 5, what is the estimated PASP?
A: 20mmHg
B: 25 mmHg
C: 30 mmHg
D: 72 mmHg
E: 105 mmHg

51. Question 7
A patient with a VSD undergoes TTE. BP measured at the time of the study is 125/75 (right arm), MAP 92. CW doppler across the VSD gives a peak velocity of 5 m/s. Assuming RA pressure of 5, what is the estimated PASP?
A: 20mmHg
B: 25 mmHg
C: 30 mmHg
D: 72 mmHg
E: 105 mmHg

52. VSD Hemodynamics Peak gradient = 4 x v2 (Simplied Bernoulli equation)
VSD gradient = LV systolic pressure – RV systolic pressure
RVSP = LVSP - VSD gradient
RVSP = cuff systolic BP - VSD gradient (or 4 x v2)
Assuming no aortic outflow tract obstruction
PASP = RVSP
Assuming no pulmonary outflow tract obstruction