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.