By M.elkhatib

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!

Sinus Venosus(superior)

Secundum

Sinus venosus(inferior)

Primum

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.