2025 – PAGE 130 – CARDIOLOGY
RIGHT VENTRICLE (RV)
The right ventricle is the main pumping chamber in utero.
CYANOTIC CONGENITAL HEART DISEASES (CCHD)
PEARL (RE: SHUNTS)
Knowing the direction of a shunt can be very difficult. For the exam, it would be surprising if you were asked to name the direction of the shunt in a complex cardiac condition. Information on the direction of shunts is presented in this guide to help you better understand the cardiac disorders. If it is too confusing, skip over the shunt information. Other topics are much higher yield.
CYANOTIC CONGENITAL HEART DISEASES MNEMONIC
Remember the cyanotic heart diseases by using your hand as a guide! Look at your hands as you review this
- 1 = Index finger = TRUNCus arteriosus
- 2 = Index & middle fingers crossed/transposed: TRANSPOSITION OF THE GREAT ARTERIES (TOGA or TGA)
- 3 = TRIcuspid Atresia
- 4 = TETRology of Fallot (TOF)
- 5 = 5 letters of TOTAL ANOMALOUS PULMONARY VENOUS RETURN (TAPVR)
- 6 = Rub the back of your Hand = HYPOPLASTIC LEFT HEART
- 7 = Rub the PALM/”PULM” of your hand = PULMONARY ATRESIA
- 8 =
= PERSISTENT PULMONARY HYPERTENSION (PPHTN) = PERSISTENT FETAL CIRCULATION: The “8” kind of looks like two “Ps” from PPHTN stacked on each other
CYANOSIS ALGORITHM AND PEARL
For cyanosis, give O2. If the child improves quickly, it is likely a PULMONARY problem. If not, give PGE FIRST and then start investigations to look for the 8 CCHDs.
PEARL: The hyperoxia test helps determine whether the cause of cyanosis is pulmonary or cardiac. After giving 100 percent inspired oxygen, if the oxygen saturation increases by at least 10 percent, this is a PULMONARY problem. If there is less than 10 percent improvement, this is a CARDIAC issue.
PROSTAGLANDIN (PGE1)
Prostaglandin (also known as PGE1 or alprostadil) is the medication given to keep the ductus arteriosus open. This may be needed when faced with a left-sided obstructive lesion (e.g., coarctation of the aorta, critical aortic stenosis, hypoplastic left heart) or a right-sided obstructive lesion (e.g., tricuspid atresia, pulmonary atresia, TOF with pulmonary stenosis).
PATENT DUCTUS ARTERIOSUS (PDA)
When a ductus arteriosus fails to close within days to weeks after birth, it’s referred to as a patent ductus arteriosus (AKA PDA). In utero, the ductus arteriosus allows for oxygen-rich blood to bypass the lungs and reach the periphery. Blood is shunted from the pulmonary artery to the aorta via the ductus arteriosus. After birth, the ductus arteriosus should close within days to weeks. If it does not, blood is shunted in the opposite direction (aorta to pulmonary artery) due to the high pressure in the aorta. A continuous “machine-like” or “rumbling” murmur is best heard below the left clavicle. Treat with INDOMETHACIN or by using a cardiac catheter and coil.
PEARL: Do not give NSAIDS, COX inhibitors or any “prostaglandin/prostacyclin synthetase inhibitors” to a patient who has a ductal dependent lesion.
MNEMONIC: “IN-DOOR”-Methicin. Come IN and CLOSE the DOOR. Meaning, indomethacin CLOSES the PDA.
MNEMONIC: PPP = Prostaglandin keeps the PDA Patent.