Pediatric Cardiology
Core concepts
Know the murmurs: innocent (soft, systolic, positional, no symptoms) versus pathologic (diastolic, pansystolic, loud, associated with failure to thrive or cyanosis). Understand shunt physiology - left-to-right (VSD, PDA, ASD) causing pulmonary overcirculation and failure to thrive, versus right-to-left (Tetralogy of Fallot) causing cyanosis. Learn ductal-dependent lesions (critical coarctation, transposition, pulmonary atresia) and the role of prostaglandin E1. Master the ECG basics of pediatric arrhythmias and the differential for cyanosis and syncope.
Traps
Questions test whether you can distinguish a benign murmur from a pathologic one using characteristics, not stethoscope location alone. Another trap is missing coarctation in a neonate who presents in shock when the ductus closes. Do not forget that a normal oxygen saturation does not exclude a cardiac cause of cyanosis if the lesion is mixing. Hyperoxia testing and the distinction between respiratory and cardiac cyanosis are frequently examined.
Worked example
A 2-week-old presents with poor feeding, tachypnea, and absent femoral pulses. This is critical coarctation until proven otherwise; start prostaglandin E1 and obtain urgent echocardiography. The trap is attributing the presentation to sepsis or feeding difficulty and delaying ductal reopening.
Rule of thumb
Diastolic murmurs are never innocent; a murmur plus failure to thrive, cyanosis, or a abnormal pulse is pathologic until proven otherwise.