Ventricular Septal Defect Flashcards
1
Q
What is Ventricular Septal Defect?:
A
- VSD is defined as a hole in the septum separating the Left and Right Ventricle
2
Q
What is the most common type of VSD?:
A
- Peri-membranous defects which typically occur in the upper membranous portion of the the Ventricular septum near the valves. = 70%
- 30% account for the other muscular defects
3
Q
What is the Pathophysiology of a very small VSD?:
A
- Very Small VSD also known as a restrictive VSD.
- Minimal Blood flow so there is no significant increase in pulmonary flow
- Asymptomatic
4
Q
What is the pathophysiology of a moderate sized VSD?:
A
- The flow of blood through the VSD is significant enough to cause an increase in blood following through the pulmonary circulation
- So there is an increase in blood flow to the LA and then the LV causing dilation
- There is also a risk of Pulmonary hypertension due to increased pulmonary preload
- Patients are at risk of congestive heart failure and arrhythmias
5
Q
What is the pathophysiology of a large VSD?:
A
- This causes a significant amount of blood to pass from the left to the right ventricle.
- Causes severe pulmonary hypertension - (the high pulmonary artery pressure drops initially which causes an increase in blood flow via the shunt and into the lungs - this in turn creates pulmonary plethora.)
- Develop early heart failure - evident in first weeks of life
6
Q
What are the risk factors for VSD?:
A
- Maternal Diabetes Mellitus
- Maternal Rubella Infection
- Alcohol Foetal Syndrome
- Uncontrolled maternal phenylketonuria
- Family history of VSD
- Trisomy 21 / Turner’s Syndrome
7
Q
What are the clinical features of a small VSD?:
A
- Patients typically have no/ mild symptoms
- May have evidence of a systolic murmur seen on a routine examination
8
Q
What are the clinical features of a moderate VSD?:
A
- Excessive sweating, easily fatigued, tachypnoea (rapid breathing)
- noticed whilst feeding
- Typically picked up around 2/3 months - due to the decrease in pulmonary vascular resistance which causes the increase in L to R shunting
9
Q
What are the clinical features of a large VSD?:
A
- Babies present with signs of congestive heart failure
- SOB, problems feeding, developmental issues (weight and height), frequent chest infections, intolerance to exercise, dizziness, chest pain, ankle swelling and a bluish complexion with clubbing
- With large VSD’s there is a possibility that Eisenmenger syndrome may be developed - which can cause severe cyanosis
10
Q
What would you expect to see on Physical Examination - Inspection of an VSD?:
A
- General Appearance: Undernourished (due to difficulties with feeding), sweat on forehead (increased sympathetic activity due to decreased cardiac output), Increased work of breathing (due to pulmonary congestion), colour (cyanotic- check tongue, nail beds and conjunctiva)
- Chromosomal Disorder - Down’s
- Clubbing
- Tachypnoea
11
Q
What are is the murmur heard in VSD?:
A
- Pan-systolic murmur which is heard in the L lower sternal border in the 3rd and 4th intercostal spaces.
- Systolic thrill may be present on palpation
12
Q
What are the causes of a pan systolic murmur?
A
- VSD
- Mitral Regurg
- Tricuspid Regurg
13
Q
What Bedside investigations would you order?
A
- ECG - May show signs of Left Ventricular Hypertrophy
14
Q
What Blood investigations would you order?
A
- Septic screen (to rule out non-cardiac causes of deterioration in children
- Kidney function assessed (ACE inhibitors, diuretics)
15
Q
What Radiological investigations would you order?
A
- CXR - can show cardiomegaly, pulmonary oedema and pleural effusions
- ECHO - Gold Standard for confirmation of diagnosis, used to determine size, location and severity
- Cardiac CT angiography with ECG gating - method of acquiring data only during specified portion of the cardiac cycle
- MRI - can determine cardiac function which is useful pre and post op
