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