Heart Development Lecture (just defects/pathology) Flashcards Preview

CPR Midterm > Heart Development Lecture (just defects/pathology) > Flashcards

Flashcards in Heart Development Lecture (just defects/pathology) Deck (27)
Loading flashcards...

Atrial Septal Defects

most ASDs result in initial (post birth) left to right shunting of blood b/c of increased blood flow returning from lungs & decreased pulmonary resistance after lungs expand


What is the result of an atrial septal defect?

shunting to R side of heart over time leads to abnormal increased blood flow to lungs

leads to pulmonary damage & pulmonary congestion, RV hypertrophy

ultimately leads to congestive heart failure


Why would cyanosis appear in an atrial septal defect?

hypertrophy of RV leads to a right to left shunt of blood so get mixing of blood


Ostium II/High atrial septal defect

90% of ASDs

hole in atrial septum caused by excessive absorption of septum I or inadequate of septum II

formaen ovale is still open


Ostium I/Low atrial septal defect

failure of up-growth of AV cushion tissue from AV septum & DMP to fill in ostium primum

have a patent ostium primum


What happens if no septa are formed?

common atria


How does cyanosis present?

clubbing of fingers
bluish fingernail beds & lips


What does cyanosis represent?

deoyxgenated blood mixing w/ oxygenated blood where lowers overall O2 content

low O2 saturation of blood that is insufficient for normal tissue physiology


What causes a double outlet right ventricle?

mal-alignment defect from insufficient shifting of AV septum or cardiac looping

both aorta & pulmonary artery exit via RV accoompanied by a ventricular septum defect


Symptoms of Double Outlet Right Ventricle

present w/ in a few days w/ cyanosis, breathlessness, murmur & poor weight gain


What is the cause of ventricular septal defects (VSD)?

failure of proper closure by abnormal or inadequate fibrous tissue


Describe the progression of a VSD

starts as L to R shunt but becomes cyanotic post birth as RV hypertrophies due to increased work load

increase RV pressure exceeds left side so now get a R to L shunt


What does complete closure of the interventricular septum require?

downgrowth of AV septum

proper formation of conotruncal ridges

interventricular muscular septum formation


What causes persistent truncus arteriosus?

failure of contruncal ridge formation & fusion (outflow tract doesn't get divided so still have opening between ventricles)

leads to VSD b/c undivided truncus overrides the R & L venticles


What does persistent truncus arteriosus present with?

pulmonary congestion
RV hypertrophy
increased R ventricular pressure
cyanotic conditions


What is tetralogy of Fallot and what are the consequences?

conotruncal ridges form off-center & leads to unequal division of pulmonary trunk & aorta

VSD (missing fibrous portion)
pulmonary infundibular stenosis
overriding aorta
RV hypertrophies in fetus


What is the most common cyanotic presenting heart defect in newborns?

Tetralogy of Fallot

b/c RV hypertrophies in the fetus due to a very small pulmonary opening


What causes transposition of great vessels & what are the consequences?

conotruncal ridges fail to spiral down

pulmonary A is connected to LV & aorta connected to RV

will only survive w/ existing shunts (VSD, ASD, patent ductus arteriosus)


What is pulmonary valvular atresia & what are the consequences?

semilunar valves are fused which leads to RV hypoplasia since the open foramen ovale is the only outlet for blood to get from R to L side

ductus arteriosus is only route for blood to get to lungs


What is aortic valvular stenosis and what are the consequences?

narrowing of aortic valve

leads to hypertrophy of LV & cardiac failure & pulmonary hypertension


What causes aortic valvular stenosis?

degenerative changes in heart


What is the significance of a bicuspid aortic valve?

aortic valve only has 2 leaflets instead of 3

results in regugitation & then to stenosis w/ aging

will eventually lead to LV hypertrophy (some develop aortic aneurysm)


What is the cause of aortic valvular atresia & what are the consequences?

aortic valves are completely fused so have hypoplastic LV

leads to wide ductus arteriosus b/c only way for O2 rich blood to gt to L side & systemic circulation


What does an aortic valvular atresia produce in the fetus v post birth?

leads to RV hypertrophy in fetus

O2 blood enters RA via ASD & enters systemic circ via patent ductus arteriosus


What occurs with a tricuspid atresia?

tricuspid valve is closed (obliteration of right AV orifice) so blood in RA can't move into RV

keeps foramen ovale open, get a VSD & hypoplastic RV, hypertrophy of LV & patent ductus arteriosus


What is seen with a hypoplastic left ventricle?

LV underdeveloped w/ absent or small bicuspid & aortic valves

ascending portion of aorta also be underdeveloped

open ductus arteriosus & foramen ovale (so can get blood to L side of heart & to lungs)


What is significant in pt with hypoplastic left ventricle?

heart works as uni-ventricular heart w/ RV doing all of the work