The diagnosis and management of fetal cardiac arrhythmias TOG 2022 Flashcards
What is define as fetal cardiac arrhythmia?
- Heart rate too fast >200 or too slow <100 or irregular rhythm.
How common? When normal Diagnosed?
3% pregnancies
At 20 weeks USS
Commenest fetal cardiac arrhythmia?
Atrial extrasystole
In clinical practice how fetal arrythmia diagnosed on imaging?
2D cardiac imaging
M-Mode ECHO
Doppler studeis
What % fetus with ectopic beats will develop sustained supraventicular tachycardia?/
2-5%
Explain 2 most common supra ventricular tachycardias?
o More common than venticualr, most often re-entry circuit or ectopic focus
o Most common 1:1 conduction – regular 240-260 – 66% fetal tachycardias – e.g. WPW
o Atrial flutter – re-entry, 25% tachyarrythmias, may or may not be regular, mostly 2:1 (80%), 200-250. Variable block, irregular and slower than 2:1 has higher risk of hydrops
Explain ventricular tachycardias
o Uncommon 1-2% tachycarrythmias, tends to be slower 1:1
o May have underlying myocardial disease e.g. myocarditis or congential conduction abnormalities
Treatment alogirth for sustained fetal tachycardia in pregnancy
Success of treatment with maternal anti-arrythmic if Hydrops or no hydrops
No Hydrops 90%
Hydrops 60%
<5% need long-term postnatal anti-arrhythmic
When should delivery be considered following treatment of fetal tachyarrythmia?
IOL from 38-40 weeks with CTG
If not controlled, CS considered as cannot monitor baby.
In the absence of structural heart disease, how common are anti-Ro/La in fetal bradycardia?
90%
Causes fetal bradycardia with 1:1 block
Long QT
Abnormality SA node
Management of fetal bradycarrythmia
What medication can be given to mothers with anti-Ro/La antqibdoies with previous effected baby?
Hydroxychloroquine < 10 weeks
Fetal ECHO 18 weeks
FH every 2 weeks from 20 weeks
