The Infant Stress Test
The other day in the ED, I saw a baby with Tetralogy of Fallot. The baby was 6 months old. He had a BT shunt and a g-tube for some earlier feeding issues. He had outgrown his tendency to aspirate, and over the past 3 days had graduated to full oral feeds, which he attacked with gusto. Unfortunately, that gusto was accompanied by diaphoresis with feeds, head-bobbing and finally, a tet spell, which brought him in to the ED. He was admitted for cardiac cath to assess for narrowing of the shunt.
Thinking about it, the timing of the events made sense. Everyone knows that adults with heart problems frequently become symptomatic with exercise. In fact, there are wonderful labs equipped with treadmills and such to evaluate adults for such tendencies.
Babies can do the same thing, they just don’t get on treadmills. But they, like adults, can become symptomatic with exercise. What exercise does an infant get in the first few months of life? The answer: feeding. If you suspect a cardiac problem in a baby you want to pay particular attention to feeding. Does the infant get tired with feeding? Is the amount per feed dropping off? Does the baby sweat during feeds, become short of breath or exhibit head-bobbing during feeds? Are there any color changes during feeds?
A yes to any of these may be a positive infant stress test.