Congenital heart defects (left to right shunts)

Question 1

What are the 3 left to right shunts congenital heart defects

Answer 1

ASD, VSD and PDA
(atrio-septal defect, ventriculo septal defects and patent ductus arteriosus

the BREATHLESS baby type
Non cyanotic

Question 2

What is ASD and Risk factors

Answer 2

2 types -
80% - Secundum ASD (foramen ovale doesnt close)
20%- Primum/ Partial - defect in the AV septum
other rarer forms - sinus venosus and unroofed coronary sinus

Small (3mm), medium (3-6) or large

1:5000 births
F>M
Maternal alcohol consumption

Question 3

Signs and Sx of ASD

Answer 3

most commonly -asymptomatic (up to 25% of population has ASD)
Not cyanotic
reccurent chest infections/wheeze
Rarely failure to thrive (if big)
Arrythmias if over 40 y/o

ESM best heard at Upper Left sternal edge +- fixed wide Splitting of S2

<10% of ASD pt can present with congestive/chronic heart failure -tachypnea, odema, fluid overload, orthopnea etc

Question 4

Investigation and management of ASD

Answer 4

CXR -larger shunts will cause cardiac enlargement with increased cardiac markins
ECG - Secundum -RBBB (MarroW) and RAD/RVH
primum- superior qrs axis

Echocardigram-diagnositic-can see the defect+shunt volume

management:

Small ASD close on their own -observe initially
if not improving by 2-5 years (usually 3)-
secundum -cardiac catherisation and occulisive device
primum-surgery

Question 5

complications and prognosis of ASD

Answer 5

Eisenmenger’s physiology-(more VSD issue) long standing L to R shunt cause pulm hypertension and reversal of the shunt-cyanotic -if operable do early, but if not -lifelong condition (cant get pregnant, fly, etc) => diuretics to reduce chances

<10% of ASD pt can present with congestive/chronic heart failure -tachypnea, odema, fluid overload, orthopnea etc

prognosis is great if no eisenmengers (inoperable)

Question 6

What are VSD and risk factors

Answer 6

Ventricular septal defects
mainly congenital but rarely aquired after MI
Classified by size - small (<3mm) and large
main types -type 2 at atrial-ventricule junction (70%), type 4 in ventricule (many small holes), type 1 (in aorta) and type 3 (big hole in middle) rarer

large has fast reversal of shunt because of pulm hypertension-> CHF

3.5 in 1000 births
RF
atrioventricular defects (AVSD) -heavily associated with downs syndrome (include VSD)
Fhx
maternal alcohol

Question 7

Signs and Sx of VSD

Answer 7

Small defect -often asymptomatic _high risk of endocarditis!
SOB, tiredness when feed, non cyanotic
“Breathless 3m-old baby, normal saturations, poor feeding with tiredness, LOUD murmur”
LOUD PAN-SYSTOLIC murmur at lower Left sternal edge
SOFT pulm S2

Large defects
Breathless baby-SOB, tachycardia
Congestive heart failure -SOB, orthopnea,
Reccurent chest infection (with clubbing cyanosis)-sign of reversal
Hepatomegaly
failure to thrive
SOFT PAN-SYSTOLIC murmur at lower Left sternal edge
Loud Pulm S2

Question 8

Investigations of VSD

Answer 8

Small - everything is normal except echocardiogram -

Large -
CXR -heart failure - ABCDE (Alveolar odema (batwing), Kerley B lines, cardiomegaly, dilated upper lobes, Pulm effusion
ECG-heart hypertrophy -R>8mm
Echocardiogram - visualise defect and shunt

Question 9

Management of VSD

Answer 9

Small -close by themselves +- ABx -after close not higher risk of Infective endocarditis

Large -try and limit apparition of Pulm HTN, HF and Eisenmenger syndrome

detected asympto -preventive closure surgery (3-6 months old)
Symptomatic- diuretics to prevent eisenmenger - Furosemide or Catopril/enalapril
+ corrective closure (3-6 months old)

Already eisenmonger
pulm dilators
abx
monitor for hyper viscosity (extra RBC because of hypoxia)
heart and lung transplant

Question 10

Complications and prognosis of VSD

Answer 10

Aortic regurg is common in some forms of VSD
Heart block -higher risk after surgery

Small VSD -infective endocarditis risk before close

prog
small -fine will close its good
Large -if progress and not closed -bad prognosis

Question 11

What is PDA and Risk factors

Answer 11

Persistance of neonate vasculature -ductus arteriosus which connects pulm artery to the aorta in utero
usually closes within 48h–PDA is after 1 month

small large or medium-depends on flow amount
above small -thickening of ventricules

1/2 per 1000

RF:
Prematurity
F>M
mother Rubella
RDS - associated with
black

Question 12

Signs and Sx of PDA

Answer 12

Presents typically around 2-3 months old -rare later
Breathless baby -SOB, apnoa, failure to thrive, Low O2
can be difficult to take off ventilator

Continuous machinery like murmur at upper left sternal angle (gibbons murmur)
Left subclavicular thrill
heaving apex beat
Bounding pulse /collapsing
BP-widened pulse pressure, low BP

Question 13

Ix and management of PDA

Answer 13

CXR - left to right shunting -cardiomegaly, increased lung markins
ECG-left atrial enlagement -deep q waves
cardiogram-see the hole

Mx -
Medical -NSAIDS -Indomatchin or Ibuprofen
Surgical (symptomatic full term babies)- surgical cathetirisation at 1 y/o

Question 14

complications and prognosis of PDA

Answer 14

Highly associated with RDS
CHF
in preterm -associated with necrolysing enterocolitis -avoid feeding if suspected PDA
assocaited with pulm hemmorhage and pulm

If closure works - prognosis normal
if closure isnt working- high death rate because of NEC,, Pulm hemmorhage, CHF -20% in first year