Acyanotic congenital heart disease: L-R shunt

Question 1

Acyanotic heart disease - what?

Answer 1

Lesions that allow blood to shunt from left to right side of the circulation or which obstruct the flow of blood by narrowing a valve or vessel

Question 2

Types of left to right shunts

Answer 2

Atrial septal defect
Ventricular septal defect
Patent ductus arteriosus

Question 3

ASD clinical features

Answer 3

Usually asymptomatic in childhood
Abnormal RV impulse
Widely split and fixed S2
Tricuspid flow murmur (diastolic, left sternal edge)
Pulmonary flow murmur (systolic, pulmonary area)

Question 4

ASD diagnosis

Answer 4

CXR - pulmonary plethora
ECG - RV hypertrophy; incomplete right bundle branch block
Echo diagnostic

Question 5

ASD Management

Answer 5

Surgical: transcatheter closure

Aims to prevent cardiac failure and arrhythmias in later life

Question 6

Small VSD clinical features and management

Answer 6

Asymptomatic
Pansystolic murmur +/- palpable thrill at L lower sternal edge
Spontaneous closure may occur but if the murmur persists at 12 months, then echo to look for associated complications

Question 7

Medium VSD clinical features

Answer 7

Symptoms during infancy: slow weight gain; difficulty feeding; recurrent chest infections
Symptoms may disappear with time due to relative or complete closure
O/E: Increased cardiac impulse; palpable thrill; harsh pansystolic murmur (also sometimes a mid-diastolic murmur due to blood flow over normal mitral valve)

Question 8

Medium VSD investigations and treatment

Answer 8

CXR - moderate cardiac enlargement; prominent pulmonary artery; increased vascularity of the lungs
Echo - position of defect
Doppler - measure shunt
Treat heart failure with diuretics and ACE-I
Surgical correction can often be avoided - base decision on several factors including severity of cardiac failure and likely progression of CVS disease

Question 9

Large VSD clinical features and management

Answer 9

Heart failure develops very early on, especially if chest infection;
O/E: Increased cardiac impulse; palpable thrill; soft pansystolic murmur (also sometimes a mid-diastolic murmur due to blood flow over normal mitral valve)
Medical tx of the heart failure
Surgical closure

Question 10

PDA - what and risk factors

Answer 10

Ductus arteriosus connects aorta to L pulmonary artery; usually closes by 4d old; PDA diagnosed if not closed after 1m
Risk factors: Preterm; down syndrome; high altitude

Question 11

PDA clinical features

Answer 11

Commonly asymptomatic
Bounding pulses
Wide pulse pressure
Murmur (initially systolic; then continuous)
If duct is large, significant shunt develops => cardiac failure

Question 12

PDA diagnosis

Answer 12

CXR - usually normal, may be increased pulmonary markings
Echo - to visualise
Doppler - to confirm ductal shunt

Question 13

PDA management

Answer 13

Can be closed at 1y in cardiac cath lab

If large, may need surgical closure at 1-3m