Cardiovascular Emergencies
Cardiovascular emergencies in children are often congenital or arrhythmic rather than ischemic. Candidates must recognize cyanotic and acyanotic congenital heart disease patterns, the ductal-dependent lesions that decompensate as the ductus closes, and the presentation of congestive heart failure in infancy (poor feeding, tachypnea, diaphoresis with feeds). Know the hyperoxia test concept and the role of prostaglandin in ductal-dependent lesions.
Arrhythmia content includes supraventricular tachycardia, which typically presents in infants with poor feeding and a heart rate that is fast and fixed, and the distinction between sinus tachycardia and supraventricular tachycardia. Understand myocarditis and pericarditis presentations and the warning signs of shock from cardiac causes.
Traps: treating supraventricular tachycardia as sinus tachycardia and missing the fixed rate; giving fluid boluses indiscriminately in cardiogenic shock; and failing to consider congenital heart disease in a neonate with shock. Another trap is assuming chest pain in a child is cardiac when musculoskeletal and pulmonary causes dominate.
Worked example: an infant with a heart rate of 280, poor feeding, and a fixed rate unresponsive to vagal maneuvers should receive synchronized cardioversion or adenosine per protocol after stabilization. Rule of thumb: a fixed, fast rate without variability suggests supraventricular tachycardia, while sinus tachycardia varies with stimulation.