30 Shunts

• ASD: RA and LA
• VSD: RV and LV
• PDA: PA and Ao

• nl pressure always higher in left
• result: if there's connection, usually left to right flow

• no cyanosis at birth

• epo release

VSD

• tiny hole: restrict the flow, loud murmur, asymptomatic
• large hole: not loud murmur but symptoms later in life

ASD

• major consequence: add volume to right side of heart
• increased flow across PV/TV causes systolic ejection murmur

• shun run: take samples of different chambers to see O2 sat
• ASD: step up at RA O2 sat because of blood mixing
• VSD: step at at RV

Secundum

• located in middle of wall: mid septum

Primum

• left: septum primum fusion with EDC
• right: non fusion, ASD
• seen in endocardial cushion defects, collective defects in down syndrome

• hole located lower

PDA

• constriction of smooth muscle closes

• differential: cyanosis in lower extremities but not upper, if untreated for years

• blood drops much more during diastole to create wider pulse pressure

• tetralogy/pulmonary atresia: cyanotic baby because not enough blood to lungs
• alprostadil used to drive blood from aorta to PA

Others

• shunt: blood shunted from left to right

• very small shunting: no HF/eisenmenger
• echo: RA on left, LA on right