VSD Flashcards
What is the most common congenital cardiac malformation?
VSD
In what percentage of patient do VSDs occur?
32% of patients, either in isolation or with a range of other malformation
What four components is the ventricular septum made up of?
1) Membranous/Perimembranous
2) Trabecular/Muscular
3) Outlet/infundibular septum
4) Inlet/AV Canal/AVSD
What are the most common types of VSDs?
Perimembranous (80% of VSDs)
Where can perimembranous VSDs further extend to?
Inlet or outlet
How are outlet VSDs subdivided?
VSD outlet defect with anterior deviation of the outlet septum (e.g ToF, associated with aortic override) and those with posterior deviation (as seen with aortic arch interruption)
Where can Muscular VSDs be situated?
Completely surrounded by muscles; frequently multiple Inlet Trabecular apical or anterior part of septum
What is a sub arterial VSD = Outlet VSD = infundibular = supra cristal VSD?
Located beneath the semilunar valves in the outlet septum. Deficiency of infundibular septum resulting in an area of fibrous continuity between the semilunar valves. Often associated with progressive AR due to prolapse of the aortic cusp, usually right.
What factors affect the pathophysiology of a VSD?
Size of VSD
PVR relative to SVR, which determines magnitude and direction of flow through the defect
Effect of small VSD with a high resistance to flow
Small left-to-right shunt and minimal haemodynamic disturbance
Effect of large VSD with no pulmonary outflow tract obstruction
Large left-to-right shunt
Low PVR
High SVR
What increases a left-to-right shunt in a VSD?
Higher SVR (e.g. aortic coarctation)
or
LVOTO (e.g valvular, sub or supravalvular AS)
What causes the direction of the shunt to reverse in VSDs?
When PVR becomes higher than SVR
Clinical findings in Very small VSD
ESM at LSE
Clinical findings in small VSD
Thrill: +
Murmur: PSM loud LSE radiating to apex
Clinical findings in moderate VSD
Thrill: + Murmur: PSM, LSE to apex with mitral MDM Apex: LV+ S2 obscured by mitral ECG: LV+, LA+, LAD CXR: Increased CTR, plethora
Clinical findings in Large VSD
Thrill: No Murmur: ESM at upper LSE and mitral MDM Apex: LV+ , RV+ S2 single with increased P2 ECG: LV+, LA+, RV+ CXR: Increased CTR, plethora, prominent PAs
Clinical findings with pulmonary vascular obstructive disease (Eisenmenger)
Thrill: No Murmur: None or soft ESM Apex: RV++, palpable pA S2: Single loud palpable P2 ECG: RV+, RA++, RAD CXR: Increased CTR, no plethora, large central PAs
Where is an inlet VSD?
Inlet of the ventricular septum, immediately inferior to the AV valve apparatus, typically occurs in Down Syndrome
What determines direction and magnitude of VSD shunt?
PVR
Size of defect
LV/RV systolic and diastolic function
Presence of RVOTO
VSD clinical presentations in adults
- VSD operated in childhood without residual VSD
- VSD operated in childhood with residual VSD
- Small VSD with insignificant L-R shunt without LV volume overload or PHTN which was not considered for surgery in childhood
- VSD with L-R shunt, pHTN, LV volume overload
- Eisenmenger syndrome
Complications of residual VSD
- IE (2/1000 Pt years, 6x higher than normal population)
- Heart failure due to LV volume overload prolonged L-R shunt
- Double chamber RV
- Subaortic stenosis
- RCC prolapse –> AR
- arrhythmias inc CHB
Treatment Options for VSD
- Surgical closure (mostly pericardial patch) with good long-term results is the treatment of choice
- Transcatheter closure
Which patients should undergo surgical VSD closure?
1) Patients with symptoms that can be attributed to L-R shunting through the (residual) VSD and who have no severe Pulmonary Vascular disease
2) Asymptomatic patients with evidence of LV volume overload attributable to VSD
Which patients should be considered for surgical VSD closure?
1) Patients with history of IE
2) VSD-associated prolapse of AV cusp causing progressive AR
3) Patients with VSD and PAH with net L-R shunt (Qp:Qs >1.5) present and PAP or PVR <2/3 of SVR (baseline or when challenged with NO or after targeted PAH therapy)
When should surgery be avoided?
Eisenmenger VSD
Exercise-induced desaturation is present
If VSD is small, not outlet VSD, does not lead to LV volume overload of PAH and if there is no history of IE
When should trans-catheter VSD closure be considered?
1) Increased risk factors for surgery, multiple prev cardiac surgical interventions or VSDs that are poorly accessible for surgery
2) Muscular VSDs that are located centrally in inter ventricular septum
3) Perimembranous VSDs
Which patients with VSDs should get annual follow-up?
LV dysfunction, residual shunt, PAH, AR, RVOTO, LVOTO
What follow-up should patients with a small VSD (native or residual, normal LV, normal PAP and asymptomatic) and no other lesions have?
3-5 year intervals
What follow-up should VSD device closures have?
Regular follow-up during the first 2 years and then depending not he result, every 2-4 years
What follow-up should Surgical VSD closures have (without residual abnormality)?
5 year intervals
Are there exercise/sport restrictions I patients with small VSD (w/o pHTN/Significant arrhythmias or LV dysfunction) or VSD closure?
No restrictions.
Patients with PAH must limit themselves to low-intensity recreational activity/sports
Is pregnancy contraindicated in patients with VSD?
Pregnancy is contraindicated in Eisenmenger syndrome?
Risk is low in asymptomatic patients with normal LV and no PAH.
Recurrence rate of CHD is 6-10%
Is IE prophylaxis recommended for patients with VSD?
Only for high risk patients.
What is Eisenmenger syndrome?
Occurs when increased pressure of blood flow in the lung becomes so great that the you develop a cyanotic R-L shunt.
Increased PVR and decreased compliance of Pulmonary vessels –> elevated PASP –> RVH –> RH pressure > LH pressure
What is a double chamber RV?
Hypertrophied RV muscle bundles divide the RV cavity into high pressure proximal chamber and low pressure distal chamber that can lead to PBF obstruction (RVOTO) and RV cavity obliteration
For which type of VSD is TTE least useful?
small apical muscular VSD
By what age do membranous VSDs partially or completely close?
Age 20
Outlet VSDs
Beneath the pulmonary and aortic valves
Never close spontaneously and risk of AR 2.5 x more common than membranous VSD
Inlet VSDs
Account got 5-8% of VSDs
Located posteriorly int he inlet septum
Extends from annulus of TV to attachments of the leaflets
Large and do not close spontaneously
Single defect unless in settings of AV septal defects
Which VSDs do not spontaneously close?
Inlet and Outlet VSDs
Membranous VSD
Most frequent VSD (75-80%) Defect inferior to AV Borders the septal leaflet of the TV Aneurysm of ventricular septum Partial or complete closure up to age 20 Extends to inlet or trabecular septum
Muscular VSD
5-10% of all VSDs Trabecular portion of septum (from inlet septum to apex) High rate of spontaneous closure Difficult to visualise and repair May be single or multiple 'Swiss cheese'
When would you perform cardiac catheterisation in a patient with VSD?
1) To assess shunt severity
2) Degree of RVOT obstruction
3) Reversibility of PHTN
What is a restrictive VSD?
Small defect that allows little or no blood flow from left to right side of the heart
