30 Shunts

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• 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

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• no cyanosis at birth

• epo release

VSD

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• tiny hole: restrict the flow, loud murmur, asymptomatic

• large hole: not loud murmur but symptoms later in life

ASD

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• 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

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• 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

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• shunt: blood shunted from left to right

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• very small shunting: no HF/eisenmenger

• echo: RA on left, LA on right