cyanotic lesions Flashcards
what are the five congenital cyanotic cardiac lesions?
truncus arteriosus transposition of the great arteries (TGA) tricuspid atresia tetralogy of fallot total anomalous pulmonary venous return
truncus arteriosus
- what
- a/w what acyanotic lesion ALWAYS
- how does HF occur
separate aorta and pulmonary artery don’t form
ALWAYS a/w VSD
more blood in pulmonary circ
transposition of the great arteries
- what
- a/w what acyanotic lesions
the spiral don’t form right, so aorta attached to RV and pulmonary attached to LV
forms 2 separate systems: 1) deoxy blood through right heart and aorta to body 2) oxy blood to and from lungs
only way to survive is a PDA/PFO
50% have a VSD too
tetralogy of fallot
- what
- a/w what acyanotic lesion
- murmur
- right POV - from infundibular septum displacement narrowing the right outflow tract:
RVH, pulmonary stenosis, overriding aorta, VSD - pulmonary stenosis so LUSE ejection systolid +/- VSD, so holosystolic murmur at LLSE
TAPVR
- what
- a/w what acyanotic lesion
- murmur
- pulmonary veins drain into right heart instead, so everyone gets mixed ox blood
- ASD/PDA - as they allow blood to get to body
- ASD, so ejection systolic at LUSE
tricuspid atresia
- what
- a/w what acyanotic lesions
- murmur
- tricuspid don’t form right > no blood in RV
- incompatible with life unless has ASD and VSD. will get right ventricular atrophy
- ASD, so ejection systolic at LUSE
when do the cyanotic lesions present?
birth to first few weeks of life
BUT ToF related to pulmonary stenosis severity, so if mild, could present later!
what is Eisenmenger’s syndrome?
initial left to right shunt
then get pulmonary HTN
so eventually RHP > LHP … then get reversal into a R>L shunt
e.g. ToF
pathogenesis of neonatal cyanosis - four ways
1) O2 can’t diffuse across alveolar membrane e.g. oedema
2) blood can’t get to lungs - R to L shunt, intrapulmonary shunt
3) lungs not ventilated - airway / pulmonary / neurological
4) V/Q mismatch - e.g. PTX, parenchymal disease
neonatal causes of early vs mid systolic click
Early systolic click
Semilunar valve stenosis
Bicuspid aortic valve
Truncus arteriosus
Mid systolic click
MVP
Ebstein’s anomaly
CXR findings:
- boot shaped
- egg on string
- snow man sign
- boot shaped = TOF
- egg on string = TGA
- snow man sign = TAPVR
what is the hyperoxia test, and what kind of results suggest cardiac vs pulmonary cause?
Hyperoxia test = after 10 minutes of breathing 100% O2, take right arm, preductal (radial artery) ABG
- PaO2 <70 mmHg – occur in most cyanotic defects
- PaO2 >150 mmHg – suggests cyanosis NOT due to CHD
which of the congenital cyanotic lesions cause increased vs decreased pulmonary blood flow? so what do they present with?
Increased BPF = truncus arteriosus, TAPVR, TGA
- Present with heart failure
Reduced PBF = TOF, TA, Ebstein’s
- Present with cyanosis
di george a/w which congenital cyanotic lesions?
TOF
truncus arteriosus
extra-cardiac complications of cyanosis
- polycythaemia
- iron deficiency
- clubbing
- clots
- cerebral abscess
- thrombocytopaenia
- hyperuricaemia
explain tet spells
feeding/exercising/crying for whatever reason causes SVR drop > inc systemic flow vs pulmonary flow > less O2 > breath more > inc VR > cycle»_space; can cause death
decreased intensity of murmur
worse cyanosis
surgical complications of TOF repair
- Bleeding
- Pulmonary valve regurgitation
- CCF – more common in setting of transannular patch
- RBBB (due to R ventriculotomy)
- Complete heart block < 1%
what are some things to use to manage tet spells?
- squatting: traps blood in the legs, decreasing systemic venous return and increasing SVR
- morphine - reduces the hyperpnoea
- vasoconstrictors
- beta blockers!!
Key risk of tetralogy of fallot?
arryhthmia!
what is the most extreme TOF variant? % of TOF cases?
15-20% - TOF with pulmonary atresia + VSD
TOF with pulmonary atresia:
- whats the problem
- how do they present
- no flow through pulmonary artery: complete R to L shunt
- lungs get blood from either a PDA (so obviously use prostin) or collaterals. Need ASD / PFO to get blood from RA to LA
- present cyanotic from birth with either no murmur, a faint continuous murmur from collaterals, or a click from enlarged aortic root
ECG findings tricuspid atresia
RAH
LVH
** superior QRS axis and LAD **
what kind of Mx is critical for pulmonary atresia?
PGE2 to keep PDA open
ebstein anomaly most associated with what maternal thing?
maternal lithium use
ebstein anomaly - what’s the abnormality
portion of tricuspid in the RV
portion of RV IN the RA (atrialised RV)
ALL will have ASD/PFO
ebstein anomaly - consequences
RV is shit
can have RVOT from TR
so you get no pulmonary flow (unless have PDA)
a/w WPW
ebstein anomaly
- murmur
- rhythm
- ecg
- CLASSIC triple or quadruple rhythm – widely split S, split S1, S3 and S4
- soft holosystolic TR murmur at LLSE
murmur of TGA
usually silent
if has VSD
- pansystolic murmur LLSE
- PS/LVOT soft mid systolic murmur - can have holosystolic murmur
type of ventricular hypertrophy with D-TGA
RVH after few days of life
BVH if have large VSD/PDA as these can cause LVH
surgery to fix D-TGA
arterial switch
LV needs to have good enough pressure to support the system
L-TGA - describe the anatomy
ventricles and and AV valves are switched:
i. Systemic venous blood > RA > mitral valve > LV > PA
ii. Oxygenated blood > LA > tricuspid valve > RV > aorta
iii. Coronary arteries have mirror image distribution
long term complications of L-TGA
tricuspid gets saggy and TR with RV failure bc of high pressures they weren’t anatomically supposed to have to withstand
classification of TAPVR subtypes, and consequences on presentation
supracardiac 50% - mildly obstructive only
infracardiac 20% - obstructive lesion from tortuous course, often through liver
cardiac 20% - different presentation to other types; 6wk with FTT
mixed 10%
what is the biggest determinant of clinical presentation for TAPVR?
whether or not there’s obstruction to pulmonary venous drainage
No obstruction:
- mild cyanosis + FTT.
- widely split S2 (high RV volume). pulmonary stenosis ES @ LUSE. mid diastolic LLSE from inc tricuspid flow
- snowman sign on CXR
Obstruction
- cyanosis and resp distress in neonatal
- …cardiac signs usually minimal
- RAD + RVH
PBF and PVR effects in truncus arteriosus
high PVR e.g. at birth > lower PBF > cyanosis more obvious
then lower PVR > high PBF > development of heart failure
double inlet ventricle
- also known as what?
- what is the defect?
double inlet ventricle = single ventricle = unilateral heart both atriums connect to one ventricle most common = connect to left ventricle, L-TGA i.e. aorta with RV and pulmonary artery with LV, but the valves dont switch - mitral still with aorta and pulmonary artery still has TV
what kind of procedures are needed for a double inlet ventricle?
initial palliative - type will depend on presence of pulmonary stenosis
- -> PS = BT shunt from aorta to pulmonary artery to improve PBF
- -> no PS = can band PA to reduce PBF or again PA-to-aorta anastamosis to improve PBF
second stage palliative
definitive is fontan at 18-24mo
Most common cause of death from cardiac defects in the first month of life is…?
HLHS
syndromes HLHS associated with?
Turner, Trisomy 18, Jacobsen’s syndrome
key pathologies of HLHS, and associated abnormalities (4)
Key characteristics
i. Hypoplasia of the LV – completely nonfunctional
ii. Atresia or critical stenosis of the aortic or mitral valves
iii. Hypoplasia of the ascending aorta and aortic arch
Associated features
i. ASD/foramen ovale (15%)
ii. VSD (10%)
iii. Coarctation (75%)
iv. High prevalence of associated CNS abnormalities (30%)
what anomaly is a requirement for survival in HLHS?
ASD/PFO and PDA - if not the pressure is way too high in the LA, and there’s also nothing coming out of the left ventricle
major findings of a HLHS in terms of Ix
metabolic acidosis
RVH on ECG
CXR pulmonary oedema
management of HLHS
- PROSTIN
- correct acidosis
- surgical
surgical management of HLHS
staged:
- norwood a birth - connect PA and aorta so one outlet from RV, so at least body can get blood. connect PA and branch of aorta so lungs still get blood
- BCPC
- definite Fontan at 3-4yo
indications for a fontan procedure
single ventricle physiology
a. Dominant RV
i. HLHS (mitral/aortic atresia)
b. Dominant LV
i. Double inlet left ventricle (DILV) = single ventricle
ii. Pulmonary atresia with intact ventricular septum (PAIVS)
iii. Tricuspid atresia
ideal saturations post fontan, and why
between 70-80% Qp:Qs = 1
if its too high, then pulmonary flow too high, and systemic low
single ventricle pathologies don’t have the ability to incease CO well
how do you know when to move from stage I to II of the fontan?
sats dropping - child has outgrown their shunt
describe the BCPC
bi-directional cavo-pulmonary shunt = Glenn. SVC attached to pulmonary artery, so the heart doesn’t have to pump blood into the heart anymore
what happens in the stage III fontan?
SVC remains attached to PA as per stage II
then IVC attached to PA via conduit
fenestration can be made between conduit and atrium
