Flashcards in Session 3 Deck (25):
What is an atrial septal defect (ASD)?
An opening in the septum between the two atria of the heart
What causes an atrial septal defect?
Failure of the foramen ovals to close after birth or an abnormal communication
What is ostium primum ASD?
An atrial septal defect in the inferior part of the atrial septum
What is ostium secundum ASD?
An atrial septal defect caused by a failure of the foramen ovale to close
What is a patent foramen ovale?
A form of ASD where the foramen ovale is present, usually as a flap valve which closes the hole in the septum due to the pressure difference between the atria
What is a paradoxical embolism?
An embolism which moves from the venous circulation into the arterial circulation via an atrial septal defect, usually a patent foramen ovale
What is a ventricular septal defect (VSD)?
AN opening in the interventricular septum
What is the most common site of a VSD?
The membranous portion of the interventricular septum
What is a patent ductus arteriosus (PDA)?
Failure of the ductus arteriosus to close after birth so blood can flow directly from the aorta to the pulmonary artery
Why is a mechanical murmur heard constantly in patients with. PDA?
Aortic pressure is always higher than pressure in the pulmonary artery so blood moves constantly from the aorta into the pulmonary artery causing a murmur
What can chronic left to right shunting to lead to?
- Vascular remodelling of the pulmonary circulation and increased pulmonary resistance
- If pulmonary circulation pressure rises above systemic circulation pressure direction of shunting will reverse
What is Eisenmenger syndrome?
Reverse in the direction of shunting in the heart when pulmonary pressure rises above systemic pressure
What is coarctation of the aorta?
Narrowing of the aortic lumen in the region of the ligamentum arteriosum
What can coarctation of the aorta like lead to?
- Left ventricular hypertrophy due to increased after load on the left ventricle
- Femoral pulse is usually weak and delayed due to reduced blood flow
- Usually upper body hypertension as vessels to the upper limbs and head often emerge proximal to the coarctation
What is a cyanotic heart defect?
A defect which causes reduced oxygen concentration in the blood
What is tetralogy of fallot?
A group of 4 lesions occurring together as a result of a developmental defect placing the outflow portion of the intraventricular septum too far in the anterior and cephalad directions
- Overriding aorta
- Pulmonary stenosis
- Right ventricular hypertrophy
What causes cyanosis in tetralogy of fallot?
VSD and overriding aorta cause right to left shunting
What determines the magnitude of shunting and level of severity of tetralogy of fallot?
The severity of pulmonary stenosis
What is tricuspid artesia?
Lack of development of the tricuspid valve leaving no inlet to the right ventricle
What must patients with tricuspid atresia also have in order to survive?
- Complete right to left shunting of all blood returning to the right atrium (ASD or PFO)
- VSD or PDA to allow blood flow to the lungs
What is transposition of the great arteries?
Right ventricle is connected to the aorta and the left ventricle is connected to the pulmonary artery resulting in 2 unconnected parallel circuits
How can transposition of the great arteries become compatible with life?
A shunt must be present to allow communication between the two circulations: patent ductus arteriosus and/or an atrial septal defect
What is hypoplastic left heart?
Failure of the left ventricle and ascending aorta to develop
What must be present for a hypoplastic left heart to be compatible with life?
A patent foramen ovale or atrial septal defect and a patent ductus arteriosus