position of the great arteries, or a shunt (but only if the right ventricle pressures are higher than the left ven tricle pressures through the shunt, e.g., tetralogy of Fallot). Aortic coarctation can cause differential cyanosis if it is preductal and the ductus fails to close. The other pathologies are either "things left open" (ASD, VSD, PDA), or "things not fully opened" (aortic and pulmonic stenosis). "Things left open" can lead to increased left-to-right flow, which can result in pul monary hypertension and right heart failure. "Things not fully opened" can lead to increased work of the chamber ejecting through the stenosed valve and sub sequent heart failure.
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