Lecture 3 - Congenital Heart Disease Flashcards
what causes murmurs at rest?
disturbed flow
what causes tetralogy of fallot?
single developmental defect placing the outflow portion of the iv septum too far in the anterior and cephalad directions
what is an acyanotic defect?
doesn’t result in lower than normal concentration of oxygen in the blood
what is an atrial septal defect?
opening in the septum between the two atria that persists following birth
what is the purpose of the foramen ovale?
allows right to left shunting of oxygenated blood before birth
why is an ostium secundum asd (at the foramen ovale) acyanotic?
left atrial pressure is higher than right atrial pressure so flow will mostly be left to right, so there’ll be no deoxy blood mixing with oxy blood being pumped around the circulation
what is a patent foramen ovale?
foramen ovale doesn’t close
generally clinically silent because higher left atrial pressure causes functional closure of the flap valve
what is the clinical consequence of a pfo?
may allow a route for a venous embolism to reach the systemic embolism if right pressure increases
what is a ventricular septal defect?
opening in the iv septum, mostly in the membranous portionbecause left ventricular pressure is higher than right, allows left to right blood flow
what is the role of the ductus arteriosus?
shunts blood from the pulmonary artery to the aorta before the lungs are functioning
what is a patent ductus arteriosus?
the ductus arteriosus doesn’t close
allows blood flow from aorta to pulmonary artery
what is the result of chronic left to right shunting?
vascular remodelling of the pulmonary circulation
increase in pulmonary resistance
what is eisenmenger syndrome?
resistance of pulmonary circulation increases above systemic
shunt reverses direction as pressure on the right side increases
result of vsd
what is coarction of the aorta?
narrowing of aortic lumen in the region of the ligamentum arteriosum
what is the result of a narrowed aorta?
increased afterload on the left ventricle
left ventricular hypertrophy
reduces blood flow to the body
what four conditions come under the tetralogy of fallot?
vsd
overriding aorta
pulmonary stenosis
right ventricular hypertrophy
how does pulmonary stenosis causes rv hypertrophy?
rv must operate at higher pressure to pump blood through the pulmonary artery
how does tetralogy of fallot cause cyanosis?
increased right side pressure, vsd and overriding aorta allow right to left shunting so deoxy blood mixes with the oxy blood being pumped round the circulation
what is tricuspid atresia?
lack of development of tricuspid valve so there is no inlet to rv
complete right to left shunt of all blood returning to ra (by asd or pfo)v
sd or pda allows blood flow to lungs
what is transposition of the great vessels?
two unconnected parallel circulations rather than two in series
rv connected to aorta and lv to pulmonary trunk
not compatible with life after birth unless a shunt exists to allow the two circulations to communicate
what is hypoplastic left heart?
lv and ascending aorta fail to develop properly
pfo or asd are also present
blood supply is via a pda
lethal without surgical correction
