Congenital Heart Disease

Question 1

APPROACH to infant with suspected CHD:

Answer 1

Silent tachypnoea’ = cardiac. Distress = resp
___

< / > 1 month?
–> <1 month, duct-dependent
–> >1 month, mixing/shunt

Colour
–> BLUE: Cyanotic (R–> L, or mixing)
–> PINK: Congestive HF (L–>R or R obstruct)
–> GREY: Systemic shock (outflow obstruction or pump failure)

4 limb pulses and BP

Pre and post-ductal sats
–> R hand and a foot
–> Differential >10% + R –> L shunt (duct-dep)= give prostaglandin

Hyperoxia test
–> 100% O2 for 10 mins
–> Minimal response = R –> L shunt (duct-dep) = give prostaglandin
(Duct-dep may actually crash with O2- pulm vasodilation at expense of systemic flow)

ALL:
Glucose
Septic work up
CXR
ECG: RVH, LVH

MX:
- O2 aim sats 85% (DON’T OVERDO)
- Prostaglandin if <1mo- won’t make them worse if you’re wrong
- Antibiotics
- Echo

Question 2

What is duct-dependence?

Answer 2

ASSUME if <1mo and cyanotic/ shocked —> give prostaglandin

DA shunts from pulmonary artery to aorta- ie. bypasses lungs.

CHD with duct dependence relies on DA for either systemic or pulmonary flow.

In first few days of life, as duct closes, will become shocked or cyanotic

Hyperoxia test:
- Won’t respond to supplemental O2 (R –> L shunt)
- May crash (pulm vasodilation and flow at expense of systemic flow)

Question 3

Dose of prostaglandin for duct-dependent CHD

Answer 3

Prostaglandin E1
10 nanog/kg/minute

Apnoea, hypotension…. be ready

Question 4

DDx for cyanosed infant:

Answer 4

CARDIAC:
- Cyanotic heart disease:
–> 5 Ts
–> Hypoplastic L heart, Pulmonary atresia, Eisenmonger etc.*

CARDIAC:
- Cardiogenic shock: myocarditis, valve, acidosis, SVT…
- Persistent pulmonary HTN

RESP:
- CAP
- RDS, TTN
- Mec asp
- Diaphragmatic hernia
- Pulmonary hypoplasia
- Airway obstruction
- PTx
…..etc.

OTHER:
- Methemglobinaemia

Question 5

What is a hypercyanotic spell?

Answer 5

Can occur in any cyanotic heart disease (not just TOF)

Triggered by reduced SVR or increased PVR–> blood ‘pulled’ or ‘pushed’ R to L.
–> Feeding, crying, straining…

Self-limiting 15-30mins

MANAGEMENT: reverse the flow
Reduce PVR:
- Console and calm
- Provide O2
Increase SVR:
-Legs to chest

________

If refractory:
Reduce tachypnoea:
- Morphine
- Sedation
Increase SVR:
- Fluid bolus
- Pressors

Question 6

What are the anatomical abnormalities in Tetralogy of Fallot? When and how does it present?

Answer 6

PROVe
Pulmonary valve stenosis
RVH
Overriding aorta
VSD

Presents with cyanotic spells- can be at birth, or not for months. (+other nonspec)

Boot shaped heart on CXR

Question 7

What are the CYANOTIC heart diseases:

Answer 7

The 5 T’s

Tetralogy
Transposition
Truncus arteriosis
Total anomolous pulmonary venous return (TAPVR)
Trisucupid atresia

+
- Hypoplastic L heart
- Eisenmonger
- Pulmonary atresia

Question 8

What are the ACYANOTIC heart diseases:

Answer 8

The Abbreviations

ASD
VSD
AVSD
PDA
CoArc
AS