Atrioventricular Septal Defect Flashcards
(27 cards)
Defintion
Abnormalities of the structures derived from the embryologic endocardial cushions, including a variety of anomalies of the atrial and ventricular septa and the adjacent parts of the MV and TV resulting in right heart volume overload.
Also referred to as atrioventricular canal defect, complete or partial endocardial cushion defect
Prevalence
- 4 to 5 % of congenital heart defects
-40% occur in children with Downs syndrome
- slight female predominance
Embryology
A flaw in the development of the endocardial cushions. The cushions contribute ti the formation of the atrial septum, ventricular septum, septal leaflets of the tricuspid valve, and the anterior MV leaflet
Complete:
ostium primum atrial septal defect, inlet ventricular septal defect, common atrioventricular valve (most common)
3 types
Rastelli Type A
chordal attachments to crest of interventricular septum
Rastelli Type B
Chordal attachments to an anomalous papillary muscle in the right ventricle
Rastelli Type C
Free floating leaflet with attachments to papillary muscles on both sides of the interventricular septum.
Unbalanced
complete atrioventricular canal defect with a dominant ventricle and an underdeveloped ventricle
Partial
ostium primum asd with a cleft MV/TV
Incomplete
two separate atrioventricular valve orifices, left ventricle to right atrial shunt, three leaflets with cleft in atrioventricular valve (rare)
pathology/ physiology
-similar to those expected of ASD, VSD, or both, with the possibility of atrioventricular valve regurgitation
-LV - RA shunt possible
-Atrioventricular valve regurg is usually present
Associated conditions
*PDA
*ToF (10%)
*ASD (secundum)
- Situs ambiguus (asplenia)(Ivemark’s syndrome: right isomerism)
*Situs ambiguus (polysplenia)(left isomerism)
*Double orifice MV
*Persistent Lt SVC to the coronary sinus
*Pulmonary Stenosis (partial)
*Discrete subaortic stenosis (partial)
*Down syndrome (complete type)
*DiGeorge syndrome
*Ellis van Creveld syndrome
History
Downs syndrome
CHF
Failure to thrive
Recurrent respiratory infections
Physical Examination
CHF
Dyspnea
Fatigue
Tachypnea
Growth failure
Tachycardia
Hyperactive cardiac impulse
recurrent respiratory infections
hepatomegaly
Apical Systolic thrill (MR)
Cardiac Auscultation
- Single S1
- fixed splitting of S2
Accenuated P2
-S3
- Pulmonary flow murmur
- Atrioventricular regurgitation along left lower sternal border
-Systolic murmur (ex: VSD)
-Mid diastolic rumble at left lower sternal border or apex (due to increased flow across atrioventricular valves)
EKG
- sinus rhythm
- first degree av block
-left axis deviation (characteristic for partial atrioventricular septal defect)
-biatrial enlargement
- RBBB
-RVH, LVH, or combined
Chest Xray
-cardiomegaly with increased pulmonary vascular marking
-main pulmonary artery is prominent
- increased pulmonary vascular markings
Cardiac Cath
- LV angio confirms diagnosis
-Evaluates atrioventricular valve regurgitation
-confirms vsd size and location
-aortogram to rule out PDA (most common in Downs syndrome)
-evaluates for pulmonary htn
Natural History/ Complications
- arrhythmias (20%)
-CHF (VSD, ASD, physiology w atrioventricular valve regurgitation
-recurrent pneumonia
-infective endocarditis
- PHTN
-may develop pulmonary vascular occlusive disease in late childhood or as young adults
Medical Management
- treat CHF (diuretics, digitalis)
-prophylaxis for infective endocarditis
Surgical mangement
Palliative
- Pulm artery banding
Corrective
-Closure of ASD
-Closure VSD
-Reconstruction of cleft atrioventricular valves
-replacement of MV
Echo views
apical/subcostal four chamber, parasternal/subcostal short axis of the MV, parasternal/subcostal short axis of the left ventricle at the papillary muscle level
M-mode/2D
-utilize multiple views to determine location and diameter of shunts
-RA/RV dilation
- Right ventricular volume overload (RVE w paradoxical septal motion)
-D shaped LV indicating RV volume overload
-Elongated LVOT (goose neck deformity)
-atrioventricular valves insert at same level
-ostium primum atrial septal defect (partial/complete AV canal)
-cleft mv/tv (partial AV canal)
-Inlet VSD (complete/transitional AV canal)
-commone atrioventricular valve or annulus(complete AV canal)
-determine number of atrioventricular leaflets (usually 5)
-determine chordal attachment locations
-determine papillary muscle architecture (may appear turned counterclockwise in short axis view)
-Determine RV/LV dimensions
- determine the presence of associated lesions
PW/CW/Color doppler
- determine the location, direction, and magnitude of shunt
-determine the severity of regurgitation
-determine the presence and severity of LVOTO due to chordal attachments
