Pediatric Cardiology
What to master
Distinguish cyanotic from acyanotic congenital heart disease by physiology, not just lesion lists. Know the five classic cyanotic lesions (tetralogy of Fallot, transposition, tricuspid atresia, total anomalous pulmonary venous return, truncus arteriosus) and the duct-dependent lesions where prostaglandin E1 is life-saving. Understand shunt physiology: left-to-right shunts cause pulmonary overcirculation and heart failure; right-to-left shunts cause cyanosis. Master murmur timing and location-systolic ejection (aortic/pulmonary stenosis), holosystolic (VSD, mitral regurgitation), continuous (PDA), and diastolic (aortic/pulmonary regurgitation).
Concepts that recur
Tet spells are treated with knee-chest position, oxygen, and morphine to increase systemic vascular resistance. Transposition presents with cyanosis unresponsive to oxygen and requires PGE1. Coarctation shows differential blood pressures and weak femoral pulses. Kawasaki disease is a cardiology emergency because of coronary aneurysm risk-know the diagnostic criteria and IVIG plus aspirin. Rheumatic fever diagnosis uses Jones criteria. Know ECG basics: prolonged QT, first-degree block, and supraventricular tachycardia in infants.
Traps
Examiners test murmur vs physiology mismatch-a loud murmur is not necessarily serious, and a silent lesion (e.g., transposition) can be lethal. Another trap is hyperoxia testing: a cyanotic newborn who does not improve with oxygen suggests fixed right-to-left shunt. Beware attributing feeding difficulty and sweating to gastrointestinal disease when they are signs of heart failure in infants.
Rule of thumb
Cyanotic newborn who does not respond to oxygen → think transposition and start PGE1. For any infant with poor feeding, sweating, and tachypnea, examine the heart before the gut.