Cardiac Situs And The Segmental Approach Flashcards
Label these three images in terms of Cardiac position.
From left to right
- Dextroposition
- Mesoposition
- Levoposition
Which position is this? And label the image?
- Apex position
From left to right
- Levocardia
- Mesocardia
- Dextrocardia
What is the difference between the two images?
The left is a normal situs and the right is dextrocardia
What does this image demonstrate?
Dextrocardia in sub 4CH
Label the images in terms of Visceral Situs?
What does this image demonstrate?
VSD with overriding Aorta
What are segments? 4
The anatomical structures which the cardiovascular structure system is divided for purposes of evaluation which include:
1. Systemic and pulmonary veins
2. Atria
3. Ventricles
4. Great arteries
What does connectives describe?
The anatomical sequence of the structures
What does connections include? 3
- Venous to atria (veno-atrial)
- Atria to ventricle
- Ventricle to great arteries (ventriculo arterial)
What does concordants describe?
Normal Sequential relationship between the hearts chambers, valves, and great vessels
What is a term used for concordant?
Appropriate
What does discordant refer to?
Abnormal sequential relationship between chambers, valves, great vessels
What does commitment describe?
The degree of abnormality of flow through the valves into ventricles and great vessels
What is an example of commitment?
A valve which overrides a large VSD is committed to more than one ventricle
Commitment is assigned based on what rule?
50% rule
In terms of commitment if more that _____% of a valve overrides a VSD, it is said to be committed
50%
What does ambiguous mean?
When precise identification of a chamber can not be determined
What are inlet/outlet anomalies? 2
Anomalies of structure and flow
1. Into the ventricle (inlet)
2. Out of the ventricle (outlet)
What are things we would see in terms of congenital heart defects in the first 8 weeks of development? 4
- Looping
- Twisting
- AV canal formation
- Septal formation
What is a segmental approach to CHD?
A systematic approach to defining and characterizing congenital heart defects
What does segmental approach to CHD focus on?
Focuses on segments of the heart and connections between them
How does segmental approach to CHD differ from old classification system?
Differs based on the associated abnormalities
What are three steps for segmental approach of CHD?
- Visceral atrial situs + atrial connections
- Orientation of the ventricles + connections
- Orientation of the great vessels + connections
What does cardiac position mean?
Where the heart lies within the chest
What is right dextroposition?
Most of the heart lies to the right of the sternum
What is midline mesoposition?
Heart lies directly behind the sternum
What is left levoposition?
Most of the heart lies to the left of the sternum
What is normal cardiac position?
Left - levoposition
The apex may still point to the left in any of these cases
What does Step 1. visceral atrial situs refer to?
The position of the atria in relation to the nearby anatomy
In terms of step 1. Visceral atrial situs, it is standard to start with what window?
Subcostal view
What do we look at during step 1. Visceral atrial situs?
- Identify which way the apex is pointing
- Identify atria
- Relate to surrounding structures
What is cardiac position?
The direction the apex points
What is right- dextrocardia?
Apex points to the right side of the body
What is midline mesocardia?
Apex lies under the sternum
What is Left Levocardia?
Apex points to the left
What is the normal cardiac orientation?
Left levocardia
What is the process to determine dextrocardia? 4
- Start with a transverse subcoastal sweep
- Determine visceral situs
- PLAX
- Label RT chest for the reading physician
How many people are afflicted with Dextrocardia?
1:12000 people
If all organs are mirrored the correct term is what?
Dextrocardia situs inversus totalis
Individuals with Dextrocardia may be prone to what? 4
- Esophageal, bronchial, cardio pulmonary disorders
- Endocardial cushion defect
- Pulmonary stenosis
- Double outlet RV
What is a situs solitus (normal) visceral situs?
- LT sided: Stomach, spleen, pancreas
- RT sided: Liver, cecum, appendix
What is a situs inversus visceral situs?
Mirror image of normal
What is situs ambiguous?
- Inconsistent organ placement
- Duplication/absence of organs
What is atrial situs solitus (normal)?
Morphologic RA is on the RT of the morphologic LA
What is Atrial situs inversus?
Morphologic RA is to the LT of the morphologic LA
What is atrial situs ambiguous?
Confident assignment of morphologic left and right atria cannot be made
What does morphologic mean?
Has morphologic features of that chamber
What are some morphologic RA features that are defining? 5
- Eustachian valve
- Venae cave
- Coronary sinus
- Chiari network
- RA appendage
What are some definitive morphologic LA structures? 2
- Pulmonary veins
- LA appendage
What do we use to evaluate with venous segments position? 5
- Hepatic veins
- IVC
- SVC
- Coronary sinus
- Pulmonary veins
What are some identifiable features of veno-atrial connections? 2
- Systemic venous return (SVC/IVC)
- Pulmonary venous return (Pulmonary veins)
What are morphologic RV features? 7
- Crescent shaped
- TV (3 leaflets)
- Large apical trabeculations
- Multiple small papillary muscles
- Moderator band
- Septal leaflet apically displaced
- Infundibulum
What features define the morphologic LV? 5
- Bullet shaped
- MV (2 leaflets)
- Two papillary muscles
- May have false tendons
- Inlet and outlet valves in continuity
What is the crux?
Where the atria and the ventricles meet at the center of the heart
What is a bi-ventricular?
One atrium connected to both ventricles
What is uni-ventricular?
Both atria connect to one ventricle
What is common curx?
Atria connect to ventricles through a single multi-leaflet structure
What are some things we look for in terms of Ventriculo- arterial concordance? 4
- AV and PV anatomically identical
- Look for fibrous continuity between AV and MV
- Look for overriding vessels
- Assess spatial relational of AV/PV in SAX
In terms of ventricular-arterial connections, what are 3 main variations from normal?
- Transposed connection
- Double outlet connection
- Single outlet connection
What is a transposition of the great arteries in terms of ventricular arterial connections?
- Main PA arises from the LV
- Aorta arises from the RV
In terms of Ventriculo-arterial connections, what is double outlet connections?
Both the great arteries arise from a single ventricle (almost always the RV)
In terms of ventriculo-arterial connections, what is a single outlet connection? 2
- Only 1 overriding great artery (aorta) coming from the ventricle
- Great arteries are fused into a single truncal artery with branches from the ventricle
What are some defining features of the pulmonary trunk?
Bifurcations to the branch PAs in the
1. LPA
2. RPA
What are defining features in the Aorta?
- Coronary arteries
- Branches (innominate a, LCC, LSC)