[DrSeddik]

A mother of a 2 week old male infant brings her baby to the ER, and says that he can't take his breath. You take a look at the patient to find him cyanosed and in respiratory distress. When you ask his mother when this started she burst in tears, and she says that it started very soon after he was born by an illegal midwife because the mother couldn't pay much for the delivery and she thought that his bluish color is just temporary and will go away in time, but it only got worse. She also told you that it's all her fault because she is a diabetic and she heard that children of diabetics tend to be abnormal.

On examination, you heard the sound attached by ausculatation of the heart. You took the patient to cardiology and you watched the echo, the cardiologist told you that the condition is caused by failure of the aorticopulmonary septum to spiral. He also told you not to give him a high concentration of oxygen and to give prostaglandins. Which of the following is true:

a- There should be preferential cyanosis with the upper limbs more cyanotic than the lower limbs
b- There should be preferential cyanosis with the lower limbs cyanosis deeper than the upper limbs
c- On chest x ray the heart should be hugely enlarged
d- The mother's diabetis has nothing to do with the fetal condition
e- The cardiologist doesn't know what he is talking about

 

[fauzan]

emm... coarctation along wid PDA????

i ll go wid option B.....


i thought it to be machinery like murmur wid a loud systole....

 

[smile135]

c- On chest x ray the heart should be hugely enlarged ?

 

[indian]

TOF is likely here

The attached heart sounds file sounds like a drum melody from a sub Saharan African tribe
Anyway, I think it indicates a long systolic murmur with a single S2 which goes with a VSD and pulmonary stenosis which makes me think of tetralogy of fallot which is also caused by failure of development of the aortopulmonary septum. Also the clinical presentation goes with that.
However, I can't find any of the options appealing
Perhaps D is the most logical answer coz as far as I know maternal diabetes does cause truncus arteriosus but not TOF.
It's a very interesting question, where did you get it from sedik!

 

[DrSeddik]

I was gonna post this with the answer, but since it's interfering with figuring out the question ,and it should ... then...
The heart sound is not for an infant ofcourse, the heart rate is no where near 90, but there's one main abnormality in the media and you can figure out the rest from written clinical picture.

 

[lemontea88]

Could it be C?

 

[dr pinky]

'C' i think

 

[DrSeddik]

The mother being Diabetic (choice d), cyanosis starting just after birth and failure to of the aorticopulmonary septum to spiral all point to TGA (transposition of the greate artery). In F4 cyanosis usually starts about three weeks after birth.

The heart sound is not for an infant, and not for this case, but it shows machinary, or train in a tunnel (a drum melody from a sub Saharan African tribe ) continuous murmur with systolic accentuation, a PDA. Sometimes there is a difficulty to know wether the diastolic murmur is really a murmur or just a background noise and the patient has only systolic murmur (VSD). Well if you have this difficulty there are specific clues; if the heart sound is heard over the left sternal border it's probably VSD, while PDA murmur is heard inferior to the left clavicle. VSD murmurs are accentuated by hand grip (increased afterload). In this case there were'nt any of these clues, however the cardiologist saying not to give him high concentration of oxygen and give him PGs is to keep the PDA open; PDA needs relative hypoxia to stay open, and endomethacin might cause intrauterine closure of ductus arteriosus, onthe other hand, iv Prostaglandins help keep the ductus open. In TGA you need any connection between the LV-Pulmonary art.-lung-pulmonary vein-LA circulation and RV-aota-systemic circulation, PDA brings oxygen from the first well oxygenated circulation to the second one (note that the pulmonary artery here is backed up by the powerful LV with higher pressure generated), keeping the patient alive. Another clue is the booming S2 noticed by Petite, which usually accompanies PDA due to Pulmonary circulation overload created by the shifted blood from the higher pressure aorta, and the pateint is on a high way to pulmonary hypertension city, I don't think this should be the case in this patient, but in most other PDAs it is.

TGA is usually not associated with cardiomegaly (choice c), but an egg on side x ray.

I am really tired ot typing, the rest of the answer cannot be better expained than it is downpage in a similar thread called Differential Cyanosis , I realized that after I finished with typing the question. Just remember before you answer a question with a PDA, determine the blood flow through it (from aorta to pulmonary or the reverse)

The correct answer is a . The high yield info are in bold.

 

[khanar]

That's a great question man
Thank you very much
I'll never forget it

 

[DrSeddik]

That's a great question man
Thank you very much
I'll never forget it

Thanks... I am glad to hear that..

 

[fauzan]

WOWEEE!!!! although i got da option wrong but i was on da ryt track.....

but DR. seddik.... Pathological Basis of disease says in infantile PDA... da cyanosis is localised to the LOWER LIMBS...

????????????????

 

[DrSeddik]

WOWEEE!!!! although i got da option wrong but i was on da ryt track.....

but DR. seddik.... Pathological Basis of disease says in infantile PDA... da cyanosis is localised to the LOWER LIMBS...

????????????????

http://www.usmle-forums.com/usmle-step-1-bits-pieces/805-differential-cyanosis.html

 

[fauzan]

thanks man!!!

 

[vibs]

its called Reverse Differential cyanosis

WOWEEE!!!! although i got da option wrong but i was on da ryt track.....

but DR. seddik.... Pathological Basis of disease says in infantile PDA... da cyanosis is localised to the LOWER LIMBS...

????????????????

Reverse differential cyanosis occurs when transposition of the great arteries is combined with pulmonary hypertension and a patent ductus. In this setting, the desaturated blood enters the ascending aorta from the right ventricle and the saturated left ventricular blood enters the descending aorta via the patent ductus.