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 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: 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

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: Size: Shunt: Muscular Large / Non-restrictive 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