Neonatal physiology - direction shunt - pulmonary resistance and blood flow - ventricles work
What cardiac problems can cause hydrops foetal or fetal loss inutero?
Changes in physiology during transition from fetal circulation to neonatal circulation (post birth)
What cardiac problems cause critical illness within first 24 hrs and how do they present?
Ebstein’s anomaly
Cardiomegaly, massive (wall to wall) on CXR
Presents w resp distress in first 24 hrs
Secondary pulmonary hypoplasia due to compression of lungs by heart
TAPVD = Total anomalous pulmonary venous drainage
Types & presentation
Mx
Rare form of congenital heart disease where all four pulmonary veins drain to the systemic venous circulation
→ Supracardiac (most common) drain into SVC, later presentation of mild cyanosis -> CCF later down the track. CXR = snowman sign
→ Cardiac: drain into RA
→ Infracardiac drain into IVC, present as severe cyanosis and heart failure/shock in first 24 hrs of life if obstructed (infra cardiac drainage into IVC). CXR - white out or diffuse pulm congestion/plethora
Mx
Murmurs presenting in first 24 hrs of life
Pulmonary or aortic stenosis
Mitral or tricuspid regurg
*Not ASD or VSD (can’t hear them at this stage, wait until pulm pressures fall ~2-6wks)
*TGA and hypoplastic L heart - single S2 but murmur may be absent early on
Duct dependent lesions when do these usually present?
24hrs to 2 weeks
1. Dependent on PDA for pulmonary blood flow
2. Dependent on PDA for systemic blood flow
3. Dependent on PDA for mixing
Ix for cyanotic neonate when ?TGA vs respiratory condition
CXR
ECG
Hyperoxia test (put them in high O2 conditions and see if they oxygenate
+/- Echo
Congestion on CXR in first 2 weeks of life - ?differential
TAPVD w obstruction
Mildly plethoric lung fields / narrow mediastinum (boot shaped heart) on CXR in first 2 weeks of life - ?differential
TGA
Oligaemic lung fields on CXR in first 2 weeks of life
?differential
Pulm stenosis
Pulmonary atresia etc
TGA
P/w cyanosis/hypoxaemia/tachypnoea within first day of life, progressively more severe as duct loses
Tx
+/- balloon septostomy (catheter through groin, blow up balloon and rip a hole in atrial septum) to aid mixing
Pulmonary atresia
Pulmonary valve is ‘blocked’
Presents w cyanosis (but often picked up antenatally)
ECG - tall p waves
Tx
Conditions that present at 2-6 weeks of life
What is this due to (physiology) how do they present?
Due to decreasing pulmonary vascular resistance
Present with congestive heart failure
Sx of congestive heart failure in baby
Tachypnoea
Poor feeding
Tachycardia
Diaphoresis with feeds
Poor weight gain
Hepatomegaly
Truncus arteriosus
Sx are due to EXCESSIVE pulmonary blood flow
Present - 2-6 weeks of life when pulm vasc resistance drops and pulm blood flow increases with pulmonary over-circulation and signs of CCF: mild cyanosis, tachypnoea, tachycardia, resp distress, hepatomegaly
Signs: ejection click and systolic murmur, single loud second heart sound, and a diastolic murmur if truncal valve regurgitation is present (50% of pts, worsens sx). Bounding peripheral pulses from excess runoff into pulm arteries.
CXR - pulmonary plethora, cardiomegaly
ECG - RVH/LVH
Echo - can see large VSD and common trunk
Red flag features on examination of a child with a murmur
Signs of CCF:
ASD murmur features
Presents 2-6 weeks
Hyperdynamic precordium
Fixed split S2
Ejection systolic flow murmur at USB
+/- diastolic rumbling murmur at LLSB
Coarctation murmur and exam features
Short systolic murmur at LLSB
+/- systolic ejection click if bicuspid aortic valve
Murmur heard posteriorly
Diminished femoral pulses
Radio-femoral delay
HTN upper arms relative to lower limbs
Over time - cyanosis, tachypnoea, signs of HF
Characteristics of innocent murmurs in older children
Healthy child (no exercise intolerance, no resp infections, no family hx)
No signs of heart failure or cyanosis
Normal precordium (not hyperdynamic, no thrills or heaves)
Pressure overload vs volume overload in VSD vs ASD
VSD murmur
Pansystolic harsh/blowing murmur at LLSB + palpable thrill +/- apical diastolic rumble
Rheumatic heart disease