Please enable JavaScript.
Coggle requires JavaScript to display documents.
Cyanotic CHD (right-to-left shunts) - Coggle Diagram
Cyanotic CHD (right-to-left shunts)
Tetralogy of Fallot
most common cause of cyanotic CHD
4 cardinal anatomic features
large VSD
overriding aorta
pul stenosis
right ventricular hypertrophy
most dxed antenatally or after finding a murmur in 1st 2mo of life
late infancy features
severe cyanosis
hypercyanotic spells
may lead to MI, CVA, death
irritability
inconsolable crying
SOB
pallor
usually self limiting + followed by sleep
if prolonged (>15min) require prompt tx
morphine
IV propranolol
IV fluids
bicarb
muscle paralysis + artificial ventilation (reduces metabolic O2 demand)
squatting on exercise
rare to see in developed countries
clubbing will develop in older children
loud harsh ejection sys murmur @ left sternal edge from day 1 of life
investigations
CXR
small heart
uptilted boot shaped apex due to right ventricular hypertrophy
right sided aortic arch
pul art "bay" - concavity where you would normally find pul art
decreased pul vasc markings due to reduced pul blood flow
ECG
normal @ birth
right ventricular hypertrophy when older
ECHO
will demonstrate cardinal features
cardiac catheterisation may be required to show detailed anatomy of coronary arts
Management
definitive surgery @ 6mo
close VSD
relieve right ventricle outflow tract obstruction
if v cyanosed in neonatal period need a shunt to increase pul blood flow
Modified Blalock-Taussig shunt: surgical placement of artificial tube between subclav art + pul art
balloon dilatation
Transposition of the great arteries
discordant ventriculo-arterial connection
aorta connected to right ventricle
pul art connected to left ventricle
2 parallel circulations
incompatible with life unless another anomaly achieves mixing e.g. VSD, ASD, PDA
features
cyanosis always
may be profound + life threatening
less severe if other anomalies
presentation usually on d2 of life - ductal closure
2nd heart sound loud + single
usually no murmur
investigations
CXR
narrow upper mediastinum
"egg on side" appearance of cardiac shadow
increased pul vasc markings due to increased pul blood flow
ECG usually normal
ECHO essential
management
PG infusion
balloon atrial septostomy
renders flap valve of foramen ovale incompetent
all require surgery - arterial switch procedure in neonatal period
Hyperoxia (nitrogen washout) test
determine presence of heart disease in cyanosed neonate
100% O2 for 10mins
if PaO2 remains low you can dx cyanotic CHD
Immediate management
ABC
artificial ventilation if necessary
PG infusion
maintenance of ductal patency = key for survival
SEs = apnoea, jitteriness, seizures, flushing, vasodilation, hypotension
