Ventricular Septal Defect Flashcards
What is the most common Congenital Heart Defect?
Ventricular Septal Defect (VSD)
What is VSD?
Congenital hole in septum between ventricles
What direction is the shunt in VSD? Why?
- L –> R
- Because pressure in L ventricle > R ventricle
What are the different types of VSD? (3 things)
- Very small VSD (aka Restrictive VSD)
- Moderate sized VSD
- Large VSD
What happens in a Very small VSD (aka Restrictive VSD)?
Blood flow thru VSD so minimal so no significant increase in pulm blood flow
What happens in a Moderate sized VSD?
Blood flow thru VSD great enough to cause increase in pulm blood flow
What part of heart contraction is the Shunt in VSD happening in?
Systole
What is the pathophysiological steps of Moderate sized VSDs complications? (6 steps)
- L-R Shunt in systole
- Extra blood pumped directly into pulm circulation
- So no initial effect on R ventricle
- L heart receiving greater volume of blood
- L Atrium + Ventricle dilation
- Risk of CHF + Arrhythmias + Pulm HTN
What can the Pulm HTN from VSD lead to in the heart?
R ventricle wall hypertrophy as pumping against high pulm pressure
What is the pathophysiology of Large VSDs complications? (2 steps)
- Significant amount of blood passing thru L-R shunt
- HF + Severe Pulm HTN
When will you see signs of HF in a Large VSD?
After first wks of life
How do you get CF of HF from VSD? (3 steps)
- Initially high pulm artery pressure drops
- More blood allowed thru L-R shunt –> lungs
- Pulmonary Plethora + Cardiomegaly
How do you get CF of HF from VSD? (3 steps)
- Initially high pulm artery pressure drops
- More blood allowed thru L-R shunt –> lungs
- Pulmonary Plethora + Cardiomegaly
What is Pulm Plethora?
Appearance of increased pulm perfusion on CXR
What are the RF for VSD? (6 things)
- Maternal DM
- Maternal rubella (during preg)
- Alcohol (–> Foetal alcohol syndrome)
- Maternal Phenylketonuria (during preg)
- FHx of VSD
- Chromosomal abn
What are the CF of Very Small VSD (aka Restrictive VSD)?
Asymptomatic (or mild symptoms)
When would you even see a Very Small VSD pt?
When infant brought to med attention bc systolic murmur detected during routine exam
What are the CF of Moderate Sized VSD? (3 things)
- Sweating
- Fatigue
- Tachypnoea
When are CF of Moderate Sized VSD especially notable?
During feeding
What age do CF of Moderate Sized VSD appear?
2-3 months
Why do CF of Moderate Sized VSD only appear after 2-3 months?
Bc pulm vasc resistance decreases –> increase in L-R shunting
What are the CF of Large VSDs? (8 things)
- CHF symptoms
- SOB
- Feeding problems
- Dev issues (aka weight + height)
- Freq chest inf
- Clubbing
- Cyanosis (if Eisenmenger Syndrome develops)
- Haemoptysis (severe)
What murmurs might you hear in VSD? (2 things)
- Systolic murmur
- Diastolic murmur
When do Systolic murmurs of VSD occur?
Between S1 + S2
Where are the Systolic murmurs of VSD heard best?
Lower L sternal border
What is the Quality of the Systolic murmur in VSD?
Uniform high pitched
Why might you get a Diastolic murmur in VSD?
Increased blood flow thru Mitral valve –> Relative mitral stenosis
Where is the Diastolic murmur in VSD best heard?
Apex
When do Diastolic murmurs in VSD occur?
Early to mid-diastole
What are some differentials that present similarly to VSD? (6 things)
- Mitral regurg
- Tricuspid regurg
- ASD
- Patent ductus arteriosus
- Pulmonary stenosis
- Tetralogy of Fallot
How do you differentiate between VSD and Mitral regurg?
Echo
How do you differentiate between VSD and Tetralogy of Fallot?
CF of ToF more severe
What investigations can you do for sus VSD? (2 things)
- ECG
- Bloods
What will a ECG show in VSD?
Left or Bilateral Ventricular Hypertrophy
What bloods should you do for sus VSD? (3 things)
- Septic screen (to rule out non-cardiac causes of collapse / deterioration)
- Kidney function (before starting tx)
- Microarray (if chromosomal abn sus)
What imaging can you do for sus VSD? (4 things)
- CXR
- Echo
- Cardiac CT angiography
- MRI
What might you see on a CXR in VSD? (4 things)
- Cardiomegaly
- Pulm oedema
- Pleural effusion
- Pulm HTN
What is the GOLD standard imaging for confirming VSD Dx?
Echo
What will the Echo tell you about the VSD? (4 things)
- Size
- Location
- Severity
- Relation to nearby valves
What is an invasive investigation technique for VSD?
Cardiac catheterisation
What is the benefits of Cardiac catheterisation in CHDs (VSD)? (4 things)
- Dx
- Tx
- Determine relative pressures + Pulm vasc resistance
- Determine significance of shunt
What does the Mx of VSD depend on?
Size of VSD
What are the Mx options for asymptomatic small VSD?
Maintain good hygiene (to reduce risk of inf endocarditis)
What are the M EDICAL Mx options for VSD? (4 things)
- Increased Calories
- Diuretics
- ACEi (2nd stage meds after diuretics)
- Digoxin
Why is Increased Calories needed for VSD babies?
Because CHF from VSD will cause them poor feeding
How do Diuretics work to manage VSD? (2 steps)
- Reduces fluid in pulm + systemic circulation
- Relieves pulm congestion
What should you add to minimise Potassium loss with diuretics for VSD?
Spironolactone
How do ACEi work to manage VSD? (4 steps)
- Reduce systemic arterial pressures (afterload reduction)
- Allow more blood flow thru Aortic valve
- Less blood flow thru VSD
- Reduced L-R shunt
When you add ACEi to VSD Mx, what other meds should you stop and why?
- Stop Spironolactone
- Bc ACEi increase K levels
How does Digoxin work to manage VSD? (4 things)
- Tx CHF
- Increases heart muscle strength
- Helps maintain normal heart rhythm
- Removes excess water from body
When is Digoxin indicated in VSD?
Diuretics not adeq relieving CF
Do most UK centres use Digoxin in VSD? Why?
No, data on efficacy is controversial
When is Surgery indicated for VSD?
@ Qp/Qs = 2+
(pulm-to-systemic blood flow ratio)
What are the Surgical Mx options for VSD? (3 things)
- Surgical repair (open heart surgery)
- Catheter procedure
- Hybrid approach
What is the Catheter procedure for VSD Mx? (2 steps)
- Catheter inserted thru femoral artery
- Mesh device put in to close hole
What is the Hybrid approach procedure for VSD Mx? (2 steps)
- Surgeon creates small access thru LV
- Interventional cardiologist puts in mesh device
What are the Long term Mx options for VSD? (2 things)
- Maintain good dental hygiene
- Avoid non-medical procedures (piercing / tattoos)
(to reduce inf endocarditis risk)
