Normal and Abnormal Fetal Heart Flashcards
At how many weeks does the heart start to circulate?
5 weeks
When do structures fuse to form a single heart tube?
22 days
What structures separate the atria and ventricles and when do they begin to develop?
Endocardial cushions
27 days
What does the septum primum divide?
L and R atria
When is the aorticopulmonary septum formed?
7th week
When has the heart completed formation?
8th week
The UV shunts blood into what structure?
Ductus venosus –> IVC
Through what valve does blood pass to enter the foramen ovale –> LA
Eustachian valve
Where does blood go coming from the IVC versus coming from the SVC?
IVC –> eustachian valve –> foramen ovale –> LA
SVC –> TV –> RV –> PV –> ductus arteriosus –> aortic and systemic circulation
Where is the more highly oxygenated blood shunted to from the aorta?
Cranial portion
Blood in the LA is contributed by what structures?
Pulmonary veins and from RA through the foramen ovale
How to tell what side of the heart is which in a TRV view?
L side is closer to the spine
What is the term for the normal angle of the heart?
Levocardia
What typically oocurs to the heart within the chest when there is a mass lesion seen in the thoracic cavity?
Dextroposition and mesocardia
What is the term for the heart on the right side but apex is pointing to the left?
Dextroposition
In the fetal heart, will the RV or LV appear slightly larger?
RV
What structure should the foraminal flap open into?
LA
What structures does the ductal arch view encompass?
Pulmonary artery
Ductus arteriosus
Desc Ao
What valves can you see in SAX of the fetal heart?
PV
TV
Ao V
What structures encompass the aortic arch?
- Brachiocephalic A
- LCCA
- L subclavian A
- Desc Ao
What is the smallest vessel in the 3VV?
SVC
What is the most common benign fetal arrhythmia?
PAC
What is a non-conducted PAC?
Stops at the AV node
bpm in SVT?
Ratio of atrial to ventricular contractions?
180-300bpm
1:1
What heart rate is considered tachycardia in the fetus?
> 180
What heart rate is considered bradycardia in a fetus?
<100
A fetus that does not respond to treatment of SVT is at risk for what two things?
Heart failure and non-immune hydrops
What arrythmia is between 300-400bpm and has a 2:1 ratio of atrial to ventricular beats?
Atrial flutter
What arrythmia does not have a set atrial or ventricular contraction rate?
A-fib >400bpm
What heart abnormality has a normal atrial rate and slower ventricular rate?
A) 1st degree HB
B) 2nd degree HB
C) 3rd degree HB
D) Atrial flutter
3rd degree heart block
What is the term for a bradycardic rate that comes and goes?
Transient Bradycardia
What are the most common cardiac malformations?
VSD’s
In what heart abnormality is it common to see VSD’s?
TOF
What are the four types of VSD’s?
- Inlet - close to the TV’s- can detect in 4Ch view
- Outlet - most superior and close to the AoV and PV
- Trabecular AKA midmuscular or central
- Apical - Past the insertion point of the moderator band
Most common types of ASD’s in order?
- Ostium secundum - m/c
- Ostium primum
- Sinus venosus
Which ASD is most commonly associated with a AV defect?
Ostium primum as it is right next to the IVS
In what abnormality will result in fetal death without the presence of an ASD?
Transposition of the great vessels
What are AVSD’s also called?
AV canal or endocardial cushion defect
What heart abnormality is associated with all trisomies?
AVSD’s
What is the most common severe left sided obstructive lesion?
Hypoplastic L heart syndrome
What heart defect is the most common cause of death or stillbirth?
Hypoplastic L heart syndrome
What abnormality may not present until 2nd trimester?
hypoplastic L heart syndrome
What findings in the 2nd trimester is suspicious of hypoplastic L heart syndrome?
Mitral stenosis
What does RV hypoplasia generally result from?
Pulmonary atresia but can also occur due to tricuspid atresia
What heart abnormality is seen with a ductal-dependent lesion?
RV hypoplasia
What is a progressive lesion that tends to worsen as pregnancy continues?
Tricuspid atresia
What are the most common sites for Aortic coarctation?
Ductal and postductal
Describe types A, B, and C of aortic coarctaction?
A: distal to Lsubclavian artery
B: b/w L subclavian and LCCA
C: b/w LCCA and brachiocephalic trunk
Visualization of a larger RV without any other abnormalities is suspicious of what?
Aortic coarctation
What abnormality is associated with aortic coarctation?
Bicuspid Ao valve
What is the most common form of cyanotic heart disease?
TOF
Classic features of TOF? (4)
- Perimembranous VSD
- Overriding aorta
- Pulmonary atresia
- RV hypertrophy
3 types of PA abnormalities with TOF
- Pulmonary stenosis
- Pulmonary atresia with patent ductus
- Pulmonary atresia with aortopulmonary collaterals
What abnormality causes a larger RA and smaller RV?
Ebstein Anomaly due to the TV being displaced far down in the RV
What measurement between MV and TV is likely to diagnose ebstein anomaly?
> 8mm
What anomaly is associated with maternal ingestion of lithium carbonate?
Ebstein anomaly
In complete transposition, where is the Ao in relation to the PA?
Ao is to the right
In what TGA are the RA and RV concordant?
Complete transposition -
RA connects to RV which connects to Ao
LA connects to LV which connects to PA
T or F? Complete TGA is more common than incomplete TGA
True
What are the connections in the heart with incomplete TGA?
RA connects to LV which connects to PA
LA connects to RV which connect to Ao
Why does truncus arteriosis occur?
Failure of the pulmonary and aortic trunks to fuse
What chambers does the truncus arteriosis receive blood from?
LV and RV
What is the most common type of DORV?
DORV with a subaortic VSD
Where is the VSD in a VSD type DORV?
Below the aorta
Where is the VSD in a TGA type DORV?
Below the pulmonary artery
Where is the VSD in a Fallot type?
Doubly-commited meaning there is a VSD below both the PA and Ao and pulmonary stenosis
Where is the VSD in a non-committed DORV?
VSD is in a remote location
What two cardiac abnormalities will you see the Ao and PA running in parallel rather than crossing over?
- TGA
- DORV
A strong association of poorly controlled diabetes has contributed to what heart abnormality?
DORV
What is the most common fetal cardiac tumour?
Rhabdomyoma
What arrythmia is most commonly seen with a fetal rhabdomyoma?
SVT
The normal aorta should be seen crossing over the PA in which orientation?
A) Posteriorly
B) Anteriorly
C) Laterally
D) Medially
Anteriorly
How do you obtain the 3VV from a 4CH?
Move transducer cephalad
You see a defect near the SVC, what type of ASD is it?
Sinus venosus