2 - Paeds - CVS - Tetralogy of Fallot

Question 1

most common cause of ?

Answer 1

cyanotic congenital HD

Question 2

4 cardinal anatomical features

Answer 2

Large VSD
Overriding aorta wrt ventricular septum (gets RV flow too)
Subpulmonary stenosis > RV outflow obstruction
RVH as a result

Question 3

how diagnosed?

Answer 3

mostly antenatally

or following murmur in first 2m (cyanosis may not be obv at this stage but can be severe)

Question 4

Sx

Answer 4

Severe cyanosis, hypercyanotic spells and squatting on exercise developing in late infancy

Question 5

Hypercyanotic spells - lead to what 3 things if untreated? 6 things that happen?

Answer 5

MI, CVA, death

rapid inc cyanosis
irritable
crying from hypoxia
SOB and pallor due to tissue acidosis
shorter murmur

Question 6

Signs - what in older kids? what from day 1?

Answer 6

clubbing in older

loud, harsh ESM at LSE from day 1 (RV outflow obstruction, mostly muscular and below pulm valve)

Question 7

Ix - ECG and Echo? what else can be done

Answer 7

ECG - normal at birth, RVH when older
ECHO - shows 4 features,

cardiac catheterisation needed to show detailed anatomy

Question 8

Ix - CXR - shows?

Answer 8

relatively small heart
uptilted apex (boot-shaped) due to RVH
pulm artery ‘bay’ - concavity in L heart border
dec pulm vasc markings due to reduced BF

Question 9

mgmt - if severe neonatal cyanosis?

Answer 9

use shunt to increase pulm bf.
> surgical placement of tube between subclavian and pulmonary artery
OR balloon dilatation of RV outflow

Question 10

mgmt - initial? when surgery? do what?

Answer 10

initially medical
surgery at 6m
close VSD and relieve RV outflow obstruction using artificial patch across pulm valve

Question 11

How to manage a Hypercyanotic episode?

Answer 11

self limiting and followed by sleep
If prolonged - sedation and pain relief, IV propanolol (inc pulm bl fl), IV fluids, bicarb for acidosis, muscle paralysis and artificial ventilation to reduce O2 demand