Fetal Cardiac Abnormalities Flashcards
The heart begins to develop around how many weeks?
5 weeks
During the development time of the heart, paired heart tubes form and do what?
Fuse into a single heart
When does the chambers of the heart develop?
6-8 weeks
When is the heart fully developed?
10 weeks
What are three things in fetal circulation that we don’t generally have in the adult heart?
- Ductus venous
- Foramen ovale
- Ductus arteriosus
Which view rules out 1/3 of the cardiac defects?
Four chamber
If the cardiac outflows are included, then how many of the cardiac defects can be ruled out?
2/3
What are the vessels in three vessel views?
- PA
- Ao
- SVC
When is fetal echo best performed?
20-22 weeks to term
What does fetal screening of the heart allow? 2
- Alllows parental decisions and preparation
- Allows for potential medical intervention in utero and prepare for treatment post natally
Fetal screening has a huge impact for conditions with what? 3
- High risk of pre-operative mortality
- Risk of intrauterine fetal death
- Opportunity to intervene in utero
What are things that are high risk of pre-operative mortality? 2
- TGS
- Coarctation
What are risks of intrauterine fetal death? 2
- SVT
- Heart block
What are opportunities to intervene in utero? 2
- Arrhythmia
- Aortic and pulmonary stenosis
What are four indications for fetal echo?
- Abnormal fetal findings from previous ultrasound
- Family history of congenital heart defect
- Previous pregnancy with a cardiac abnormality
- Maternal diseases associated with heart defects (type 1 diabetes)
What are some fetal findings associated with heart disease? 9
- 2 vessel cord (IUA)
- Congenital diaphragmatic hernia
- Omphalocele
- Thick nuchal fold or NT
- Persistent right umbilical vein
- Hydrops
- Chromosomal abnormalities
- Bradycardia
- Tachycardia
What is the fetal echo routine? 8
- Establish situs with stomach and heart
- 4 chamber heart view
- Outflow tracts
- 3 vessel view
- Aortic arch and ductal arch
- Short axis of ventricles and atria
- SVC and IVC
- Pulmonary veins
What does normal Abdominal situs look like? 5
- Stomach bubble on left
- Desc. Aorta on left
- IVC anterior and to the right of the aortic
- Liver on the right
- Spleen behind the stomach on the left
What is the process of the cine clip of the fetal heart exam? 3
- Beginning at the level of the AC
- Slowly sweep Cephalic on the fetus
- Demonstrating anatomy (stomach, 4 chamber view, LVOT, RVOT, 3 vessel view)
When setting up the cine clip, what needs to be demonstrated at the level of the AC?
Demonstrate the fetal stomach to confirm situs
How long is a cine clip of the heat echo routine?
6-12 seconds
What is the top tip for fetal heart imaging?
Use fetal echo preset if available
Besides fetal echo present, what is some tips for fetal heart imaging? 5
- Use the highest frequency possible for your patient
- Reduce depth
- Narrow sector width/ colour box
- Reduce dynamic range
- Zoom
What is an acrynoym to help remember 4CH heart?
PASSSS
What does PASSSS stand for?
- Position: 2/3 in the left chest
- Axis: 45 degrees from midline
- Size: 1/3 of the chest
- Symmetry: RA=LA, RV=LV
- Septa: FO, IVS
- Squeeze: Qualitative assessment
In the fetal heart, the aorta arises from where?
Left ventricle
How does the aorta course in the LVOT?
Left to the right first
What is the aortic wall continuous with?
Septum
Does the aorta bifurcate?
No
What should the aortic valve look like? 2
Thin and mobile
In the fetal heart, the pulmonary artery arises from where?
Right ventricle
The fetal pulmonary artery courses how?
Anterior and to the left
Does the Pulmonary artery bifurcate?
Yes, we must see it bifurcate
What does the pulmonary valve look like?
Thin valve and mobile
What does the RVOT cross?
The LVOT at right angles
What is included in three vessel view?
From left to right and anterior to posterior:
1. Pulmonary artery
2. Aorta
3. SVC
In three vessel view, how similar is the PA and the aorta visually?
PA similar size or larger
In the 3 vessel view, the SVC and the aorta compare how visually?
SVC is smaller than aorta
In the three vessel view, What vessels dive together to left of the trachea?
Aorta and PA
What is the sizing order of three vessel view?
PA>AO>SVC
What does fetal short axis view demonstrate? 4
- Right and left atria
- Right ventricle
- Pulmonary artery
- Ductus arteriosis encircling the aorta
What does the aortic arch look like?
Candy cane
What are the three vessels in the aortic arch?
- Brachiocephalic
- Left common carotid artery
- Left subclavian artery
What does the ductal arch look like?
Hockey stick
What is the ductal arch?
When the right ventricle with ductus join the aorta
What does the SVC and the IVC do in the fetal heart?
Bring deoxygenated blood back from the body to the right atrium
What is the SVC-IVC alternative name?
Longhorn view
How many pulmonary veins do we usually see in fetal echo?
2 pulmonary veins
What is included in the fetal echo routine in terms of doppler? 4
- Inflows
- Outflows
- Ductus arteriosus
- Foramen ovale
What are four tips for pulsed doppler in the fetal routine?
- Line up the flow - parallel
- Place sampling gate after the valve
- > 1m/s consider stenosis
- Useful in rhythm assessment
What is the normal colour scale velocity for fetal valves, IVS, and venous structures? 3
- Valves: 50-80 cm/s
- IVS: 30-40cm/s
- Venous structures: ~20 cm/s
When determining the aortic arch, how do we determine the vessels?
We must determine which direction the Descending aorta and ascending aorta are
In the fetal heart, M mode is done through what?
Atrium and ventricle usually done in a four chamber view
What does M-Mode confirm in fetal echo? 3
- Viability
- Arrhythmias
- Abnormal rhythms
What are some arrhythmias that can be seen with M-mode? 2
- Heart blood
- Are the ventricles and atria contracting at the same time
What are some abnormal things that we can see in M-mode?
Premature atrial contractions
Premature atrial contractions determined in M- mode may include what? Is it malignant or benign?
- May preclude tachycardia
- Generally benign
What is considered normal in terms of BPM in fetal echo?
- 120- 160 is normal
- Up to 180 in 1st trimester is normal
What is considered bradycardia in fetal echo?
<100 bpm
What usually causes bradycardia in fetal echo?
Heart block
What is considered tachycardia in fetal echo?
> 180
What causes tachycardia in fetal echo?
Decrease in stroke volume
Fetal tachycardia is treated with what?
Digoxin to the mother
What happens to the mothers heart with digoxin?
Mothers heart will respond to the medication as well
What is a ASD?
Partial or complete absence of interatrial septum
How difficult is it to diagnose ASD?
Difficult due to the normal foramen ovale
How big should the Foramen Ovale be?
No larger than the aortic root
What is a VSD?
Complete or partial absence of ventricular septum
What is the most common cardiac anomaly in fetal echo? How much are associated with VSD?
- VSD
- 50%
What views do we use to view VSDs?
Subcostal (horizontal) 4 chamber and short axis of ventricle the best views
What is the prognosis of VSD? Why?
- Good
- May close on its own
When does AVSD occur in utero?
When the endocardial cushions fail to fuse early in embryology
The fetal heart starts with a common ventricle and common atrium that communicates through what?
The AV Canal
What is the end result of a ASVD?
1 common valve with 5 leaflets
What is absent in ASVD?
MV and TV
What is another name for AVSD?
AV canal or endocardial cushion defect
50% of fetuses with ASVD have what disorder?
T21
What is Ebsteins anomaly?
Apical displacement of the TV into the right ventricle
What is the sonographic appearance of ebstein’s anomaly? 3
- Large Right atrium
- Apical displacement of TV
- Small right ventricle (dysplastic)
What is hypoplastic right ventricle secondary to?
Pulmonary atresia without a VSD
What is the sonographic appearance of a hypoplatic right ventricle? 2
- Difficult to see inner chamber
- Small or absent pulmonary artery
What does hypoplastic left ventricle cause in terms of flow in the LV?
Decreased flow into or out of the left ventricle
What is the sonographic appearance of hypoplastic left ventricle? 3
- Small left ventricle
- Aortic stenosis or atresia
- Mitral valve atresia
What condition is hypoplastic left ventricle associated with?
Coarctation of aorta
What is often seen with hypoplastic left ventricle as pregnancy progresses?
Endocardial fibroelastosis (EFE)
How does someone get endocardial fibroelastosis (EFE)?
From muscle hypertrophy
What happens with endocardial fibroelastosis (EFE)?
Myocardium is replaced by collagen and elastic tissue
What does EFE look like? 2
- Very echogenic
- Focally thick myocardium
What syndromes is EFE seen with?
Hypoplastic heart syndromes
What does EFE cause?
Deceased cardiac function and congestive heart failure
What does Tetralogy of fallout mean?
Four things are going wrong in the heart
What four things that are seen with Tetralogy of fallout?
- VSD
- Aorta overriding ventricular septum
- Hypertrophy of right ventricle
- Pulmonary stenosis
What is Truncus Arteriosus?
Single large vessels arising from the base of the heart
What does the truncus arteriosus supply? 3
- Coronary arteries
- Pulmonary
- Systemic circulation
What are things that are seen sonographically with Truncus arteriosus? 3
- VSD
- Large overrriding aorta
- Pulmonary artery origins will vary off the aorta
What does double outlet right ventricle mean?
Aorta and pulmonary arteries arise from the right ventricle
In terms of double outlet right ventricle, variants positions of aorta is related to what?
Pulmonary artery
What is common to see in double outlet right ventricle?
VSD
What conditions is double outlet right ventricle associated with? 2 (etiology)
- MATERNAL DIABETES
- ALCOHOL ABUSE
What is transposition of the great vessels? 3
- Aorta arses from right ventricle
- Pulmonary artery arises from the left ventricle
- Outflow vessels are parallel
What are the two types of transposition of the great vessels?
- Complete (D loop)
- CORRECTED (L for Levo)
What kind of circuit is complete D loop transition?
Closed circuit (80%)
What happens with the flow of the right atrium of complete D Loop transposition?
Right atrium to right ventricle
What does complete D loop transposition look like sonographically? 2
- Great vessels are parallel rather than crossing normal
- May have VSD
What is seen with the complete L loop transposition? (Chambers)
Right ventricle is attached to left atrium
What do we look for with L loop transposition?
Look for moderator band to identify right ventricle
What is pulmonary and systemic circulation like in terms of L Loop transposition (corrected)?
Normal
What is the sonographic appearance of L-loop transposition (corrected) 2
- Parallel great vessels
- Morphological right ventricle to morphological left atrium
Is L loop transposition asymptomatic or symptomatic?
May be asymptomatic throughout life or begin to show signs of heart failure in hid life
What is the coarctation of aorta? Where is it normally located?
- Narrowing of the aortic aortic lumen
- Usuallly at the isthmus
What does coarctation of the aorta look like sonograpically? 3
- Prominent right ventricle
- Small left ventricle
- Narrowing in the aorta
What is coarctation of aorta associated with? 3
- AVSD
- Bicuspid AV
- VSD
What increases the incidence of coarctation of the aorta?
Increased incidence in moms with diabetes
What is ectopia cordis?
Heart outside of the chest cavity
What is ectopia cordis assocaited with?
Pentalogy of Cantrell
What are things that are seen with pentalogy of Cantrell?5
- Absent lower sternum
- Defect in anterior diaphragm
- Defect in pericardium
- Omphalocele
- Ectopic cordis
Cardiospelnic syndromes are also known as what? 3
- Isomeriusm
- SItu ambiguous
- Heterotaxia
What is cardosplenic syndromes?
Symmetric development of normally asymmetric organs or organ systems
What organs are affected with cardosplenic syndrome? 4
- Liver
- Lungs
- Stomach
- Heart
So what would we see with cardosplenic syndromes?
Fetus either has two left sides or two right sides
What is seen with polysplenia? 5
- Bilateral left sidedness
- Midline liver
- IVC interruption
- No IVC through the liver
- Dextro or mesocardia
What are some examples of bilateral left sidedness with polysplenia? 3
- Multiple spleens
- Left atrial isomerisum (2 left atria)
- 2 leafy lungs
Label
B. ASD
C. Pulmonary stenosis
D. VSD
E. Coarctation
F. Tetralogy of fallout
G. Endocardial cushion defect
H. D loop transposition
I. PDA
How common are cardiac tumors in utero?
Rare
What is the most common cardiac tumor in utero?
Rhabdomyoma or cardiac hamartoma
What does cardiac tumors look like?
Solid echogenic tumors usually of the ventricular septum
What might cardiac tumors do?
Obstruct outflows
What is the DDX for cardiac tumors? 4
- Cardiac fibroma
- Hemangioma
- Myxoma
- Teratoma
What is cardiomyopathy?
Muscle damage
What is cardiomyopathy results in?
Altered cardiac function
What is cardiomyopathy caused by? 4
- Viral infection
- Bacterial infection
- Metabolic disease
- Maternal Type 1 diabetes
In terms of Polysplenia with IVC interruption, what what is perfusion like?
Renal to subhepatic segment into azygous vein to SVC
With No IVC through the liver what happens to the hepatic veins?
Hepatic veins empty into the right atria
What is asplenia also known as?
Ivenmark’s syndrome
What is seen with Asplenia? 3
- Bilateral Right sidedness
- Midline liver
- Bilateral SVC
What does bilateral right sidedness mean in terms of asplenia? 2
- No spleen
- Two right lungs
In terms of heart defects with cardiosplenic sydrome, defects of which side are worse?
Defects of the heart asplenia (right sided)
Heart defects with cardiospelnic syndrome mean there is a extremely high incidence of what with asplenia?
AVSD
Almost any defect with cardiosplenic syndrome can be associated with what?
Heterotaxia
What are commonly associated cardiac defects with cardiosplenic syndrome? 5
- Transposition of great arteries (TGA)
- Pulmonary stenosis or atresia
- Common atrium
- Total anomalous pulmonary venous return with asplenia
- Complete heart block
What is Total anomalous pulmonary venous return mean in terms of blood flow?
Oxygen rich blood returns to the right atrium instead of the left.
How difficult is it to diagnose cardiosplenic syndrome with ultrasound?
Extremely difficult to diagnose in the fetus
What are some clues that may help us diagnose cardiosplenic syndromes on ultrasound? 3
- Interrupted IVC
- Large Azygous vein
- Abnormal presentation/ position of liver, heart and spleen
