Septal Defects Flashcards
(30 cards)
What does a complete atrioventricular canal (CAVC) describe?
A constellation of defects comprising abnormalities in structures derived from the endocardial cushions
In a complete AV canal, how do the atria connect to the ventricles?
Via a common (single) AV valve instead of two discrete AV valves
What are the deficiencies present in a complete atrioventricular canal?
Deficiencies in both the atrial septum (primum ASD) and ventricular septum (inlet VSD)
What significant condition does CAVC lead to?
Right ventricular pressure and volume overload and pulmonary hypertension
What percentage of cardiac malformations does CAVC account for?
~3%
Is there a sex predisposition in CAVC?
Both sexes are equally affected
What genetic condition is significantly associated with CAVC?
Down syndrome/Trisomy 21
When do patients with CAVC often become symptomatic?
In infancy due to congestive heart failure and failure to thrive
What pharmacologic therapies are used as a bridge toward surgery for CAVC?
Digoxin, diuretics, vasodilators
At what age is surgery for CAVC usually performed?
Between 3-6 months of life
How many types of CAVC are delineated based on the morphology of the superior leaflet?
3 types (Type A, B, and C)
What classification is used for the anatomic subgroups of CAVC?
Rastelli’s classification
Describe Type A CAVC according to Rastelli’s classification.
The superior bridging leaflet demonstrates chordal attachments to the crest of the interventricular septum (~50-70%)
Describe Type B CAVC according to Rastelli’s classification.
The superior bridging leaflet attaches past the crest of the ventricular septum to an anomalous papillary muscle on the right side of the ventricular septum (~3%, rare)
Describe Type C CAVC according to Rastelli’s classification.
The superior bridging leaflet demonstrates no attachments to the ventricular septum and is referred to as a free floating leaflet (~30%)
What does the term partial AV canal refer to?
Endocardial cushion defect with interatrial communication but lacking interventricular communication
Partial AV canal is also known as incomplete AV canal.
What are the characteristics of a partial AV canal?
Right and left atrioventricular valve annuli are divided into two distinct valves
This defect includes a primum atrial septal defect and a cleft of the left atrioventricular (mitral) valve leaflet.
What is the hemodynamic effect of a partial AV canal?
Left to right shunt at the atrial level
This can lead to right atrial and right ventricular dilation over time, depending on the size of the atrial shunt.
What condition can develop due to the left to right shunt in a partial AV canal?
Right atrial and right ventricular dilation
The degree of dilation depends on the size of the atrial shunt.
What type of regurgitation is associated with a partial AV canal?
Varying degrees of regurgitation of the left AV valve
The degree of regurgitation is influenced by the size of the cleft in the mitral valve.
Fill in the blank: A partial AV canal consists of a primum atrial septal defect and a cleft of the _______.
left atrioventricular (mitral) valve leaflet
What is the transitional AV canal also known as?
Intermediate AV canal
How is a transitional AV canal defined?
It is considered a variant of a partial AV canal
What are the characteristics of a transitional AVSD?
Has two separate AV valve annuli
