Module 12 : Fetal Cardiac Abnormalities Flashcards
when does fetal heart development begin and what happens during that time
- 5 weeks
- paired heart tubes form and fuse into a dingle heart
at what weeks do the heart chambers begin to develop
6-8 weeks
at what week is the heart fully formed
- 10 weeks
when can we start to detect fetal heart beat
5-6 weeks
how does the blood flow from the placenta to the umbilical arteries
- placenta»_space; umB v»_space; left portal V»_space; ductus venosus»_space; IVC»_space; rt atrium»_space; foramen ovale»_space; lt atrium»_space; lt ventricle»_space; aorta»_space; iliac artery»_space; hypogastric artery»_space; umbilical artery»_space; placenta
OR
rt atrium»_space; rt ventricle»_space; pulmonary artery»_space; ductus arteriosus»_space; descending aorta»_space; hypogastric artery»_space; umbilical artery
what are 4 clinical indications for a fetal echo
- abnormal fetal findings from a previous ultrasound
- family history of a congenital heart defect
- previous pregnancy wth a cardia abnormality
- maternal disease associated with heart defects
+ type 1 diabetes
what are 7 fetal findings associated with heart defects
- 2 vessel cord
- congenital diaphragmatic hernia
- omphalocele
- thick nuchal fold or NT
- hydrops
- chromosomal abnormalities
- bradycardia
what is the full fetal echo routine
- situs with stomach and 4 chamber heart
- 4 chamber heart
- outflow tracts
- 3 vessel view
- aortic and ductal arch
- short axis of ventricles and atria
- SVC and IVC
- pulmonary veins
- doppler (inflows, outflows, ductus arteriosis, foramen ovale)
- m-mode through an atrium and ventricle to rule out arrhythmias
what are the 3 vessels in the 3 vessel view and what should be there respective sizes
- pulmonary artery (biggest or same as AO)
- aorta (bigger than SVC or same as PA)
- SVC (smallest)
what are 2 differences between the aortic arch view and the ductal arch view
- aortic arch = three branches and candy cane
- ductal arch = no branches and hockey stick
how many heart defects are ruled out with 4 chamber heart image and how many when 3 vessels are added
- 1/3
- 2/3
between what weeks is fetal echo the best performed
20-22 weeks to term
what is a normal heart rate for a fetus
120-160 is normal
+ 180 bpm in 1st trimester
what is considered bradycardia in fetus
- < 100bpm
- due to heart block
what is considered tachycardia in fetus
- > 200 bpm
+ decrease stroke volume
+ treated with digoxin to the mother
what is the most common arrhythmia in fetus we see
- PAC
- usually benign
what is an atrial septal defect
- partial or complete absence of interatrial septum
is it easy or difficult to diagnose ASD on US and why
- difficult
- due to foramen ovale
what should be the normal size of the foramen ovale
- no larger than aortic root
what is the best view to asses IAS
- fetal subcostal
what is a ventricular septal defect (VSD)
- complete or partial abscess of ventricular septum
what is the most common cardiac anomaly
- ventricular septal defect
how many VSDs are associated with other anomalies
- 50%
what is the best view to asses VSDs
- subcostal 4 chamber and short axis of ventricle
what is the prognosis of VSDs
- good
- many resolve on their own
what causes an atrioventricular septal defect AVSD
- when the endocardial cushions fail to fuse early in embryology
- end result is 1 common valve with 5 leaflets
- aka = AV canal or endocardial cushion defect
what is a common chromosomal abnormality that occurs with AVSD 50% of time
- T21
what is ebsteins anomaly and what is common ly associated with it
- apical displacement of the tricuspid valve into the right atrium
- hydrops and pulmonary stenosis and lithium ingestion
ultrasound appearance of ebsteins anomaly
- large right atrium
- apical displacement of tricuspid valve
- small right ventricle (dysplastic)
what is hypo plastic right ventricle
- secondary to pulmonary atresia with no VSD
- extremely uncommon compared to hypo plastic left ventricle
what is the ultrasound appearance of hypoplastic right ventricle
- difficult to see in inner chamber
- small or absent pulmonary artery
what causes hypoplastic left ventricle
- due to decreased flow into or out of the left ventricle
sonographic appearance of hypoplastic left ventricle
- small left ventricle
- aortic stenosis or atresia
- mitral valve atresia
- associated with coarctation of the aorta
- endocardial fibroelastosis (EFE) often seen as pregnancy progresses
what is endocardial fibroelastosis EFE
- from muscle hypertrophy
- myocardium is replaced by collagen and elastic tissue
- seen with hypoplastic heart syndromes
ultrasound appearance of EFE
- very thick echogenic and focally thick myocardium
what does EFE cause
- decreased cardiac function and congestive heart failure
What does tetralogy mean
- 4
What 4 things are wrong in tetralogy of fallot
- VSD
- aorta overriding ventricular septum
- hypertrophy of right ventricle
- pulmonary stenosis
What view is important to check with tetralogy of fallot
- 3 vessel view
What is truncus arteriosus
- single large vessel arising from the base of the heart
What structures are supplied by a truncus arteriosus
- coronary arteries
- pulmonary
- systemic circulation
Ultrasound appearance of truncus arteriosus
- VSD
- larger overriding aorta
- pulmonary artery origins will vary off the aorta
What is a double outlet right ventricle e
- aorta and pulmonary artery arise from the right ventricle e
- various positions of the aorta related to the pulmonary artery
- VSD is common
What two things is double outlet right ventricle associated with
- maternal diabetes
- alcohol abuse
What is transposition fo the great vessels
- aorta arises from right ventricle
- pulmonary artery arises from left ventricle
- outflow vessels are parallel
- what are the 2 types of transposition of great vessel
- complete = D loop (D for dextro)
- corrected = L loop (L for levo)
What is D loop transposition/ complete
- closed circuit
- right atrium to right ventricle
- oxygenated blood wont go to the head or the body
Ultrasound appearance of D loop transposition
- great. Vessels are parallel rather than crossing
- VSD
Where does deoxygenated blood go to with D loop transposition
- RA»_space; RV»_space; Ao»_space; body/head
Where does oxygenated blood go with D loop transposition
LA»_space; LV»_space; pulmonary artery»_space; lungs
What is L loop transposition
- right ventricle is attached to the left atrium
- normal pulmonary to systemic circulation (O2 gets to the right spots)
What structure should we look for with L loop transposition
- look for moderator band
Utrasound appearance of L loop transposition
- parallel great vessels
- morphological right ventricle to morphological left atrium
Do patients present with symptoms and why
- usually asymptomatic throughout life then begin to show signs later in life
- right ventricle does not have the same pumping ability as left ventricle does
- what is coarctation of the aorta
- narrowing of the aortic lumen
- usually at isthmus
Where is the isthmus in the aortic arch
- area between the lt subclavian artery and descending aorta
Ultrasound appearance of coarctation of aorta
- prominent right ventricle
- small left ventricle
- narrowing in the aorta
What two other anomalies is associated with coarctation of the aorta and what increases chance of this anomaly
- AVSD and VSD
- maternal diabetes
Are cardiac tumors common or uncommon
- very rare
What is the most common cardiac tumors
- rhabdomyoma
- cardiac hamartoma
Ultrasound appearance of cardiac tumors
- solid echogenic tumors usually of the ventricular septum
- may obstruct outflows
- what are 4 differentials of cardiac tumors
- cardiac fibromyalgia
- hemangioma
- myxoma
- teratoma
What is cardiomyopathy and what does it result in
- muscle damage
- altered cardiac function
What 4 things cause cardiomyopathy
- viral infection
- bacterial infection
- metabolic disease
- maternal type 1 diabetes
What is ecoptia cordis and what is it associated with
- heart outside of chest cavity
- pentalogy of Cantrell
What characteristic must be met in order to diagnose an echogenic intracardiac focus (EIF) and what chromosomal anomaly is it associated with
- have to be as bright as bone
- associated with Down syndrome
What are 3 other names for cardiosplenic syndromes
- isomerism
- situ ambiguous
- heterotaxia
What is a cardiosplenic syndrome and what are the affected organs
- symmetric development of normally asymmetric organs or organ systems
- liver, lungs, stomach, heart
- fetus has either two left sides or two right sides
What is polysplenia
- bilateral left sidedness
+ multiple spleens
+ left atrial isomerism (2 left atria)
+ 2left lungs - midline liver
- IVC interruption (no IVC through liver)
+ renal to subhepatic segment to azygous vein to SVC - hepatics empty into right atria
- heart points to right or is meso cardia (midline)
What is asplenia (ivenmarks syndrome)
- bilateral right sidedness \+ no spleen \+ right atrial isomerism \+ 2 right lungs - midline liver - bilateral SVC
Are heart defects with cardiosplenic syndromes worse with rt or lt isomerism
- rt isomerism (asplenia)
- extremely high incidence fo AVSD with asplenia
- almost any defect associated with heterotaxia
What are 5 common associated defects with isomerism
- transposition fo great arteries
- pulmonary stenosis or atresia
- common atrium
- total anomalous pulmonary venous return with asplenia
- complete heart block
Is it easy or hard to diagnosi isomerism on Ultrasound and what are 3 clues to help diagnose
- very hard
- interrupted IVC
- large azygous vein
- abnormal liver, stomach or heart position
