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 ASDsby 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 atrioventricular septal 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 septal leaflet 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 chordal attachments of the tricuspid valve. Despite its proximity to the atrioventricular valves, 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 (520% 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 correction Device 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.