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Equal
R = L
Q refers to flow
Therefore Qp = Qs
Blood flow to both the pulmonary & systemic circulations is balanced.
Homeostasis maintained
When the neonate is born this septal flap should close when the resistance in the lungs drops forming a continuous septal wall between the atria, however if this does not happen this hole can be left undetected forever!
Right Collects venous blood
Supplies RV
Pulmonary (lungs)
Lower pressure
Left Collects arterial blood Supplies LV Systemic (body) Higher pressure
Acyanotic lesion
L => R shunting
Atrial level
Patients are often well with remarkably few symptoms
May have gone to the GP regarding something else.
Diagnosis confirmed via echo
Secundum ASDs—by far the most common.
Sinus Venosus ASDs – are located either at the entrance point of the SVC or IVC. It is more common to see the Superior Sinus Venosus ASD which usually is associated with anomalous right sided pulmonary veins.
Primum ASDs are located near the AV Valves and can affect the valves causing the defect to become a PAVSD. Primum ASDs or partial atrioventricularseptal defects (AVSD) mostly occur in non-Downs patients. Partial AVSD is a Primum ASD with a cleft in the LAVV (the ventricular septum is intact).
Right atrium Increased volume
Dilation
Arrhythmias
Increased pulmonary flow
High Qp:Qs ratio
Left atrium Decreased volume Decreased systemic
flow
Common congenital heart problem,
often associated with other defects.
Communication between L & R
Left => right shunting
Unbalanced blood flow
Loss of homeostasis
Right Pulmonary (lungs)
Low pressure
Thin wall
Deoxygenated
blood - 70%
Left Systemic (body) High pressure Thick wall Oxygenated blood -100%
Membranous VSD (most commonly defect 80%)
It is inferior to the aortic valve and borders the septalleaflet of the tricuspid valve, and can extend into the muscular septum (perimembranous VSD) and can be associated with AR due to prolapse of the right or noncoronary cusp into the defect.
In adults, these defects are often associated with accessory septal tissue arising from the tricuspid valve that would account for partial or complete closure of the defect (up to 60%) and, at times, aneurysm of the membranous septum
Subarterial VSD is a defect located beneath the pulmonary and aortic valve.
These defects do not close spontaneously but can get smaller because of the prolapsing right or left coronary cusp with associated increased risk of AR.
The risk of AR increases with age (87% of patients by age 20).
Inlet VSDs are large defects that separate the mitral and tricuspid valve, lie beneath both atrioventricular valves, and extend to the chordalattachments of the tricuspid valve.
Despite its proximity to the atrioventricularvalves, this defect is not associated with mitral or tricuspid regurgitation unless in the setting of an atrioventricular septal defect.
When unrepaired, this defect in adult patients is commonly associated with pulmonary hypertension.
Muscular VSDs (5–20% of VSDs) can be small or large defects, single or multiple, and located anywhere in the muscular septum.
It is the Muscular VSDs that can be closed in the cath lab.
The atrioventricular defect is a rare defect in the atrioventricular septum leading to left ventricular to right atrial shunt that has been reported following endocarditis and could be associated with tricuspid regurgitation and sinus node dysfunction.
Right High ventricular
volume
High pulmonary blood flow
Lungs become overloaded
High Qp:Qs ratio
Left Low ventricular volume Low systemic blood
flow Body is deprived of
nutrients
High pulmonary flow Low systemic flow
Pulmonary overload
Oedema – wet lung tissue
Chest infections
Increased work of breathing
Possible need for respiratory support
Difficulty feeding
Reduced delivery of oxygen & nutrients Tachycardia Normal (low) blood
pressure Peripherally cool Generally pale Reduced gut & renal
function Poor weight gain
Surgical correctionDevice closure cardiac catheter
Generally at 2-4 years of age
Fast-tracked
for small, central ASDs Day case
The amplazer device – is a self expanding device with 1 side smaller than the other.
Sizes from 1mm to 40mm
Short, uneventful ICU stay
ASD even less than VSD
Care of chest drains and pacing wires
arrhythmias
Pain – sternotomy & CDR sites
Fluid restriction - 50% post bypass
Diuretics – temporary requirement
Hypovolaemia
Reduced LV function
Pulmonary hypertension
Heart block
JET – junctional ectopic tachycardia
Blood loss during & after surgery
LV adjustment to normal blood flow
Sensitive/reactive pulmonary bed
Disturbance of conduction pathways during surgery
Hypovolaemia
Reduced LV function
Pulmonary hypertension
Heart block
Arrhythmias such as JET
Blood transfusion
Additional fluid & low dose inotropes
Increased oxygen & ? nitric oxide
Pacing Optimal electrolyte levels
& possibly amiodarone
Over time with continuous left to right shunting the lung pressures increase causing the right sided pressures to increase resulting in a reversal of the shunt.