Acyanotic vs Cyanotic Congenital Heart Defects

You separate congenital heart defects into acyanotic and cyanotic. Basically, is the baby (or kid) nice and pink, or is he or she dusky as they like to say. Sometimes the blueishness only happens when they’re working really hard, like feeding and crying (or thinking about the pathophysiological mechanisms of heart disease).

One of the important things to remember is that acyanotic heart defects can switch over if they’re left alone for too long because of pulmonary hypertension caused by the extra flow. This is called Eisenmenger Syndrome.

It’s also important to realize that many of the cyanotic lesions are duct dependent, meaning that as long as the ductus arteriosus is open, they are happy and pink. The problems start in that time 6-24h after delivery when the ductus closes. Thankfully you can keep it open by giving prostaglandin E1.

Need the ductus for systemic circulation:

  • Coarctation of the aorta
  • Critical aortic stenosis
  • Hypoplastic left heart syndrome

Need the ductus for pulmonary circulation:

  • Pulmonary atresia
  • Critical pulmonary stenosis
  • Tricuspid atresia
  • Tetralogy of fallot

Also, I realize that the 5 Ts of cyanotic heart lesions are a pentad of 6 (plus some), but mnemonics can only do so much, and the T thing is just so catchy.

For a more detailed illustration of PDAs, you can check out this doodle!

3 thoughts on “Acyanotic vs Cyanotic Congenital Heart Defects

  1. Correction: You have hypoplastic heart and coarctation of the aorta in cyanotic heart disease, these are actually classified as acyanotic heart defects that are obstructive.

    • the less frequent form of aortic coarctation (preductal type) is actually cyanotic (causing differential cyanosis with blood to descending aorta derived from pul. artery by means of ductus arteriosus)… left hypoplastic heart is a mixing lesion and is frequently classified ( at least in academics) as cyanotic… :-)

  2. i would put the aortic coarctation and hypoplastic left heart in the acyanotic clinically these present 90% of the time as NON cyanotic. I see what Dr. Alloh is saying about them being cyanotic but the odds are they are non cyanotic clinically the majority of the time. Also it would be better to classify them sepertaely as giving PG in an emergency is a lifesaving treatment as is given doubtamine or milrone (vasodilators) and you will kill a kid if you give levopher, epi or some variety of alpha constriction as you will make their afterload worse and hence the obstruction worse.

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