Congenital Heart Disease Part 6 Flashcards
What is situs solitus?
Situs solitus (rare plural: sitūs soliti) refers to the normal position of the thoracic and abdominal organs.
This will include a left-sided heart, also known as levocardia.

What is situs inversus?
Situs inversus, short form of the Latin “situs inversus viscerum”, is a term used to describe the inverted position of chest and abdominal organs.
It is called situs inversus totalis when there is a total transposition of abdominal and thoracic viscera (mirror image of internal organs normal positioning).

What is situs ambiguous?
Situs ambiguous, heterotaxy, heterotaxia
Situs ambiguus is a rare congenital defect in which the major visceral organs are distributed abnormally within the chest and abdomen.
Heterotaxy in general refers to any defect of left-right laterality and arrangement of the visceral organs.

What are the three positions of the heart in the chest?
- Levocardia (normal)
- Mesocardia
- Dextrocardia

When you are determining Levocardia (normal), Mesocardia, and Dextrocardia what specifically are you looking at?
Apex position of the heart

What is the segment by segment analysis of the heart?
- Atria
- Atrioventricular valves
- Ventricles
- Outflow Tracts (Conus = Infundibulum)
- Semilunar Valves & Great Vessels
What is Tommy Burch recommended sequence of events to identify for complex congenital abnormalities?
- Thoraco-Abdominal situs (Solitus, Inversus, Ambiguous)
- Cardiac Position (Levo, Meso, Dextro)
- Segment by Segment analysis (Atria, AV, Ventricles, Outflow, Great vessels)
For the atrium, what is situs solitus?
Normal RA and LA = Situs Solitus

For the atrium, what is situs inversus?
Mirror image of situs solitus
LA on the Right
RA on the Left

For the atrium, what is situs ambigous?
Could be one, two atrium.
Grab bag of random

What are the characteristics of the Right atrium?
Pecinate Muscles
- Pectinate muscles outside of the right atrial appendage
What are the characteristics of the Right atrium:
Right Atrial Appendage
- RAA is broad based, triangular, and anterior
What are the characteristics of the Right atrium?
Septum?
Septum Secundum (limbus of fossa ovalis)
What are the characteristics of the Right atrium
What is usually present for major vessels and landmarks?
- IVC, SVC, CS usually,
- Crista Terminalis and tinea sagittalis
For the Left atrium, where are the pectinate muscles?
Confined to the left atrial appendage
For the left atrial appendage, what is the description?
Long and narrow (Finger like)
Located more posterior
What septum is a part of the left atrium?
Septum Primum
What structures are located in the LA?
Pulmonary veins
(Exception is Anomalous venous return)
What is seen here?

Complete AV Canal
- Primum ASD
&
- Inlet VSD
What are the types of looping in terms of ventricles?
Which is normal and most common?
D and L loops
D = More common and normal
For D Ventricles
- RV is anterior and Rightwaard
- LV is posterior and leftward

How can you identify the left ventricle?
- What valve attached?
- Comment on the walls?
- What are well defined in the LV?
What does the outflow tract NOT have?
- What is in continuity?
- Mitral valve attached
- Smoother walls
- Well defined papillary muscles
- No Conus (Muscular outflow tract)
- Continuity of the MV and AV
What is seen here?

L - Transposition in the ME 4 chamber
Isolated L-TGA is “physiologically corrected” because systemic deoxygenated venous blood returns to the pulmonary circulation and oxygenated pulmonary venous blood returns to the systemic circulation.

Isolated L-TGA patients are at increased risk of what?
What do 90% of them have?
Patients with L-TGA are at increased risk for heart failure as adults due to progressive decline in systemic right ventricular (RV) function.
90% have Tricuspid valve dysfunction
What do Left Transposition of great vessel patients have a high prediliction for outside of severe TR?
Heart Block
- Have pads on in the room
What are the other name for L-TGA?
Double discordance
- Atrioventricular Discordance = RA –> LV and LA –> RV
- Ventriculoarterial Discordance = RV –> Aorta and LV –> PA
Ventricular Inversion
The ventricles are switched
Congenitally corrected transposition of great vessels
Normal in series flow anatomically (Right –> Lungs –> Left –> Systemic circulation
What is important to note with transposition patients in regards to aortic and pulmonary valves?
They are in the same plane
(see echo clip)

What % of L-TGA patients are associated with other lesions?
90%
What % of L-TGA patients have a VSD?
70-80%
What % of L-TGA patients have pulmonary outflow obstruction (LVOT obstruction)?
30-60%
What % of L-TGA patients have tricuspid valve abnormalities?
Up to 90%
What % of L-TGA patients have mitral valve abnormalities?
55%
What is the most common arrhythmia in patients with L-TGA?
Complete Heart Block
Conduction System is abnormal and unstable
What is reverse differential cyanosis?
Phenomenon usually only seen with transposition
Post ductal sats > Preductal sats
higher sats in the feet (Post ductal) > lower sats in the RUE (Right arm)

D-TGA
Do you have atrio-ventricular concordance or discordance?
D-TGA
AV Concordance - RA dumps into RV and LA dumps into LV
D-TGA
Do you have ventriculoarterial concordance* or *discordance?
D-TGA
Ventriculoarterial discordance
LV –> PA
RV –> PA
Do you have D-TGA associated with other non-cardiac anomalies?
Rarely
What percentage of D-TGA patients have VSD?
50%
L-TGA:
What % of patients have VSD?
70-80%
L-TGA:
Pulmonary outflow tract obstruction (LVOT obstruction)?
30-60%
L-TGA:
What % of patients have Tricuspid abnormalities?
~90%
L-TGA:
What % of patients have Mitral valve abnormalities?
55%
L-TGA:
What is the most common arrythmia?
complete heart block (conduction system is abnormal and unstable)
L-TGA:
What are the 3 other names?
- Double Discordance
- Ventricular inversion
- Congenitally corrected TGA
L-TGA:
Is ventriculoarterial discordance present?
Yes
L-TGA:
Is atrioventricular discordance present?
Yes
What are the 5 cardiac lesions that occur in L-TGA?
- VSD
- Pulm Outflow Obstruction
- TV abnormalities
- MV abnormalities
- Complete HB
What procedure can be done with L-TGA patients to improve TR?
Explain how this works
Pulmonary Artery banding
Pathophysiology
- PA Banding increases LV pressure by shifting the septum towards the systemic RV improving RV geometry which decreases TR
- Alters the LV/RV pressure ratio, reduces RV sphericity aand improves RV geometry –> Decrease TR
When would a women be counseled against pregnancy with L-TGA?
Systemic Ventricular EF <40% and/or NYHA Class III or IV symptoms
What is the most common cyanotic heart lesion?
Tetralogy of Fallot