Ventricular Septal Defects
ECHO CONFERENCE 5/11/11
DARRYN APPLETON
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
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)
Morphology – The Ventricular Septum
Morphology – The Ventricular Septum
1.
2.
3.
4.
5.
Membranous
Outflow
Trabecular septum
Inflow
Subarterial /
Supracristal
VSD Types
VSD Types
VSD Types
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
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)
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
Clinical Features
 Peds:
 Murmur
 Dyspnea, CHF, Failure to thrive
 Adults:
 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
Echo Example 1
Echo Example 1
t
Outlet VSD – Para long axis
Echo Example 2
Echo Example 2
Echo Example 2
Supracristal VSD, with pulm outflow tract obstruction
Echo Example 3
Echo Example 3
Echo Example 3
Echo Example 3
Echo Example 3
Echo Example 3
 Type:
 Size:
Membranous
Restrictive
Echo Example 4
Echo Example 4
Echo Example 3
Type: Muscular
Size:
Large / Non-restrictive
Shunt: RL (inc RH pressures)
RV dilated
 Eisenmengers
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
Clinical Scenarios & Recommendations
 Eisenmenger Syndrome
 Supportive
 Bosentan (Endothelin receptor antagonist) – improves
functional capacity, QOL
 Sildenafil
Penny DJ, Vick GW. Lancet 2011; 377: 1103-12
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
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
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
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
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
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
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
Question 2
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
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
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
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
Question 4
 There is no diastolic flow in this perimembranous
VSD


A: True
B: False
Question 4
 There is no diastolic flow in this perimembranous
VSD


A: True
B: False
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
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
Question 6
Question 6
 The pulmonary artery systolic pressure in this
patient with a VSD is:



A: Normal
B: Moderately elevated
C: Systemic / Supra-systemic
Question 6
 The pulmonary artery systolic pressure in this
patient with a VSD is:



A: Normal
B: Moderately elevated
C: Systemic / Supra-systemic
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
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
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