Ventricular Septal Defects Flashcards
What are Ventricular Septal Defects (VSD)?
Defects in the inter-ventricular septum that allow shunting of blood between the left and right ventricles
Where can VSDs occur?
Anywhere in the ventricular septum - they can perimembranous or muscular
What is a perimembranous VSD?
Adjacent to the tricuspid valve
What is a muscular VSD?
When the VSD is completely surrounded by muscle
How else can VSDs be classified?
By size
What is considered a small VSD?
Smaller than the aortic valve in diameter up to 3mm
What is considered a large VSD?
Same size or bigger than the aortic valve in diameter
What is the aetiology of most VSDs?
Congenital
How may an acquire VSD occur?
Post-MI or trauma
What percentage of congenital heart disease do VSDs account for?
30%
What happens during systole in a heart with VSD?
Some blood leaks from the left ventricle into the right ventricle
Where does blood that shunts from the LV to the RV then travel?
Through the lungs and back to the left ventricle
What does re-circulation of blood to the left ventricle lead to?
Volume overload of the left ventricle, rise in right ventricle pressure and volume leading to pulmonary hypertension and associated symptoms
What may occur in serious cases of VSD?
The pulmonary artery pressure can reach levels equal to the systemic circulation reversing the left to right shunt
What will reversal of the left to right shunt cause?
Cyanosis
What are the risk factors for VSD?
- Family history of congenital heart disease
- Down’s syndrome
- Maternal alcohol consumption during pregnancy
What is the typical presentation of a small VSD?
Asymptomatic with a loud pansystolic murmur at the lower left sternal edge, and a quiet pulmonary second sound
What symptoms may large VSDs present with?
- Heart failure
- Recurrent chest infections
- Tachypnoea and tachycardia
- Hepatomegaly
- Active precordium
What may be heard on auscultation in a large VSD?
- Soft pansystolic murmur
- Apical mid-diastolic murmur
- Loud pulmonary second sound
What investigations can be considered in VSD?
- CXR
- ECG
- Echo
What will a CXR and ECG show in a small VSD?
Normal
What can an echo be used for in a small VSD?
Demonstrating precise anatomy and confirming diagnosis
What will a CXR show in a large VSD?
- Cardiomegaly
- Enlarged pulmonary arteries
- Increased pulmonary vascular markings
- Pulmonary oedema
What will an ECG show in a large VSD?
Biventricular hypertrophy from 2 months
