Paediatric Cardiology Flashcards
What are the signs of asymptomatic ASD?
- Wide FIXED SPLIT S2
- Pulmonary flow murmur (ESM RUSE)
- May get tricuspid flow murmur (mid diastolic)
Note: a secundum ASD >2cm is often symptomatic
What syndrome is associated with ASD primum?
Downs/T21 (endocardial cushion defects)
What syndrome is associated with secundum ASD?
Holt Oram Syndrome (a/w TBX5)
What are the ECG findings of secundum ASD?
- 2 Ps - Peaked P waves (Lead 2/V2) and PR is long
- 2 Rs - RAD and RBBB (incomplete) / rSR’ pattern
What is the valvular issue associated with primum ASD?
Cleft anterior leaflet of the MV
What gene may be involved in primum ASD development?
Tbx1 (a/w 22q11)
What genetic syndromes are associated with ASD?
Lots!
Down Syndrome (trisomy 21) most common Holt-Oram Syndrome (usually secundum) Noonan Syndrome Ellis van Creveld syndrome Cri du chat Kabuki syndrome Trisomies 13, 18 Chondroectodermal dysplasia
What are the long term complications of untreated ASD?
R sided volume overload - RVH Pulmonary artery hypertension Increased PVR May cause paradoxical embolisation/stroke SVT, AF, flutter
What problems do retinoids cause in pregnancy and why?
Retinoids help signal embryologic body patterning therefore variety of effects in 4th week, interfere with Hox genes. Signals cardiac mesoderm position therefore causes conotruncal cardiac defects (tetralogy of Fallot, PA/VSD, DORV, DOLV, truncus arteriosus and TGA)
What gene may be implicated in DiGeorge Syndrome?
Transcription factor Tbx1
What is the DiGeorge critical region?
22q11.2
What gene(s) may be implicated in Noonan syndrome?
PTPn11 - encodes the tyrosine phosphatase Shp-2, associated with pulmonary valve stenosis
What is the approximate total (right and left) ventricular fetal cardiac output? Which ventricle is doing more?
The combined output of both the left and right ventricles—is ≈450 mL/kg/min. RV output ~ 1.3 times LV and pumping against systemic circulation
In a normal term neonate how long does the ductus take to close?
Functional closure of the ductus arteriosus is usually complete by 10-15 hr in a normal neonate,
How does the newborn increase LV output?
Hormone/metabolic. Increase in the level of circulating catecholamines and in the density of myocardial β-adrenergic receptors
What is the umbilical venous pO2 in a foetus?
30-35mmHg
What is the pO2 of the IVC blood in a foetus?
26-28mmHg (this goes across the foramen ovale into the LV and is what is used for the brain/upper body)
What % of fetal RV output actually gets to the lungs?
5%
What helps keep foetal circulation open?
What closes it?
Therapeutic agents may either maintain these fetal pathways (prostaglandin E 1 ) or hasten their closure (indomethacin)
Cardiac anomalies associated with Trisomy 21 (Down syndrome)
Commonest: AVSD
Endocardial cushion defects so VSD, ASD, AVSD, also tetralogy of Fallot
What cardiac anomalies are associated with Scimitar syndrome?
Hypoplasia of right lung, anomalous pulmonary venous return to inferior vena cava
What cardiac anomalies are associated with Noonan syndrome?
Pulmonic stenosis, ASD, cardiomyopathy.
Can also get VSD, PDA
What cardiac anomalies are associated with Williams-Beurin syndrome?
Supravalvular aortic stenosis, peripheral pulmonic stenosis
What cardiac anomalies are associated with Treacher-Collins syndrome?
VSD, ASD, PDA
What cardiac anomalies are associated with congenital rubella?
PDA, peripheral pulmonic stenosis (50%) can also cause ASD/VSD
What cardiac anomalies are associated with Fragile X?
Mitral valve prolapse, aortic root dilatation
What cardiac anomaly is associated with Trisomy 21p (cat eye syndrome)?
Total anomalous pulmonary venous return
What cardiac anomalies are associated with XO (Turner syndrome)?
Coarctation of aorta, AS, bicuspid aortic valve
What drug teratogens may a child with VSD have been exposed to in pregnancy?
Alcohol, valproate, carbemazapine, phenytoin
What cardiac anomalies might you expect from a child with fetal alcohol syndrome?
ASD, VSD
What cardiac anomalies might you expect from a child with fetal hydantoin syndrome?
VSD, ASD, coarctation of aorta, PDA
What cardiac anomalies might you expect from retinoic acid embryopathy (e.g. isotretinoin use in pregnancy)?
Conotruncal anomalies e.g. tetralogy of Fallot, pulmonary atresia with VSD, DORV, DOLV, truncus arteriosus and TGA
What cardiac anomalies might you expect from valproate use in pregnancy?
Coarctation of aorta, hypoplastic left side of heart, aortic stenosis, pulmonary atresia, VSD
What syndrome is associated with dextrocardia?
Kartagener syndrome aka primary ciliary dyskinesia.
How old do you expect a child with cyanotic heart disease to be before you see clubbing?
Clubbing of the fingers and toes is not usually manifested until late in the 1st yr of life, even in the presence of severe arterial oxygen desaturation.
What cardiac anomalies are associated with a widely split S2?
ASD (fixed split, not always widened) Pulmonary stenosis (fixed split) Ebstein anomaly Total anomalous pulmonary venous return Right bundle branch block
What cardiac anomalies are associated with a single S2?
Pulmonary or aortic atresia or severe stenosis
Truncus arteriosus (only one valve!)
TGA
If you hear an ejection click…
AS, PS
Dilated PA or ascending aorta
Mid systolic click is MV prolapse
What is the most common paediatric form of cardiomyopathy?
Dilated cardiomyopathy
Commonest age group for dilated cardiomyopathy?
<1 year old
What are the changes that occur when you transition from fetal to neonatal circulation (and why)?
- Take a first breath - open lungs increasing pO2, decreased PVR and increased pulmonary blood flow
- placenta removed from circulation increasing SVR and closing ductus venosus
- foramen ovale closes due to increased pulmonary return
- ductus shunt become left to right as LV ouput increases, usually closes at ~10-15hrs of life
How long does it take neonatal PVR to drop?
- Starts with first breath
- Biggest drop in the first 2-3/7
- Continues over weeks
What is the most common congenital heart defect?
VSD. Nelson’s says 30-35%, medscape >20%, other sources 25%
What cardiac anomalies are associated with 22q11.2 deletions?
What syndromes?
What non-cardiac anomalies?
Conotruncal defects (tetralogy of Fallot, truncus arteriosus, double-outlet right ventricle, subarterial VSD) and branchial arch defects (coarctation of the aorta, interrupted aortic arch, right aortic arch).
DiGeorge syndrome or the Shprintzen (velocardiofacial) syndrome.
CATCH 22 (cardiac defects, abnormal facies, thymic aplasia, cleft palate, and hypocalcemia). Congenital airway anomalies such as tracheomalacia and bronchomalacia are sometimes present.
How common is secundum ASD?
6-8% of all congenital heart defects.
Females > males.
May be associated with PAPVR.
What are the expected ECG findings in AVSD?
Varies depending on severity.
- LAD/superior axis
- RVH or biventricular hypertrophy
- RV conduction delay/RBBB
- Often see Q waves in Leads I and aVL
- Normal or tall P waves +/- increased PR interval
What are the types of VSD and what % do you expect to close by what age?
Membranous most common (~80%) and 35%-40% close by themselves. Small perimembranous VSD a/w increased risk aortic valve prolapse/insufficiency occasionally.
Muscular - (5-20%) and can have multiple. 80% close.
Supracristal (~5%) - the remainder! More common in Asians and males. Important because of prolapse of the aortic valve (usually R coronary cusp) into the defect and aortic insufficiency, which may eventually develop in 50-90% of these patients around the age of 5-9yo. Limits the shunting.
Describe possible presentations, examination findings, and investigation findings with small VSD.
Small: Likely asymptomatic and present with murmur. Exam - Loud/harsh or blowing holosystolic murmur LLSE, thrill, can end before 2nd sound if it closes during late systole. A short, harsh systolic murmur localized to the apex in a neonate is often a sign of a tiny VSD in the apical muscular septum.
Ix - can have normal ECG or LVH, CXR normal or slight cardiomegaly with increased pulmonary markings
NB supracristal: Exam - murmur at the mid to upper left sternal border. Aortic regurg - decrescendo diastolic murmur upper right or mid left sternal border. Severe AR - wide pulse pressure, hyperdynamic precordium.
Describe the typical clinical presentation of a medium-sized VSD:
SOB and diaphoresis with feeds age 2-3/12
Describe typical examination and investigation findings of a medium-sized VSD:
Exam - Loud/harsh or blowing holosystolic murmur LLSE, thrill, displaced apex + cardiomegaly.
Ix - ECG LVH, CXR slight cardiomegaly with increased pulmonary markings
