Congenital Heart Defects Flashcards
What are the two shunts present in the foetal circulation which allow mixing of the oxygenated and deoxygenated blood?
Ductus arteriosus
Foramen ovale
Describe the foetal circulation
The foetus receives oxygenated blood from the mother’s placenta. Because the lungs are not fully formed, the vascular resistance within the pulmonary arteries is high therefore the blood from the IVC takes the path fo elastic’s resistance and passes through the foramen ovale directly into the left atrium. A minority of blood will pass into the right ventricle and through the pulmonary vein but nearly all of this passes through the ductus arterioles into the aorta.
The chambers of the heart are identified by their characteristic and not by their position. T/F?
True
What is the difference in morphology between the appendages of the right and. left atria?
Right- broad appendage
Left - narrow, sausage-shaped appendage
What is the difference in morphology between the right and. left ventricles?
Right - heavy trabeculations, muscular band called the moderator band, chordae tendinae insert into the septum
Left - smooth endocardium, 2 papillary muscles, ellipsoid cavity
The atrioventricular valve always follows the atrium. T/F?
False - it follows the ventricle
The aortic and pulmonary valves always stay with their relevant artery and so can be connected to the wrong ventricle. T/F?
True
Give examples of acyanotic congenital heart defects
Ventricular septal defects Persistent ductus arteriosus Atrial septal defects Pulmonary stenosis Aortic stenosis Coarctation of the aorta
Give examples of cyanotic congenital heart defects
Tetralogy of fallot
Transposition of the great arteries
Atrioventricular septal defects
What is the most common type of atrial septal defect?
Secundum
Where in the atria does the hole occur in a secundum atrial septal defect?
Centre of the atria
Where in the atria does the hole occur in a primum atrial septal defect?
Close to the atrioventricular valve which can distort the valve leading to it becoming leaky or regurgitant
How can a secundum atrial septal defect lead to right ventricular failure?
Causes a left to right shunt as blood moves from a higher to lower pressure. The extra blood being received into the right ventricle causes right ventricle dilation which inhibits the ability of the ventricle to pump efficiently and will eventually cause right ventricular failure
It is not unusual for ASDs to be first diagnosed in adulthood. T/F?
True
What are the possible presentations of an atrial septal defect?
Murmur
Arrhythmia and palpitations due to stretching of right atrium
Shortness of breath
Embolic stroke
How are atrial septal defects treated?
Surgically with a sternotomy
Through the groin vessels with a transcatheter device
At what point in the aorta is a coarctation commonly seen?
Insertion point of the ductus arteriosus.
After the left subclavian artery
How can a coarctation of the aorta lead to left ventricular failure?
The narrowing of the aorta means that the left ventricle has to generate a higher pressure to push the blood through so the patient will develop left ventricular hypertrophy which can progress to left ventricular failure
What are the possible presentations of severe coarctation of the aorta?
Poor lower limb perfusion (cold feet, claudification of the legs, abdominal angina)
Headache and nosebleeds due to increased systemic pressure proximal to the coarctation
Hypertension may be the result of coarctation of the aorta. T/F?
True
What discrepancies in blood pressure may you find in a patient with coarctation of the aorta?
Upper limb pressure is greater than the lower. limb pressure
There may be radio-femoral defat in coarctation of the aorta. T/F?
True
What other congenital defects is aortic coarctation associated with?
Bicuspid aortic valve
Berry aneurysms
How can coarctation of the aorta be treated?
Surgery - narrowed aorta is cut out or reconstructed using the subclavian artery
Transcatheter - balloon passed through and inflated to stretch the narrowed artery