To place AED pads on an infant, use the front-and-back (anteroposterior) method: one pad goes on the center of the chest, and the other goes on the center of the back between the shoulder blades. This positioning is recommended because an infant’s chest is too small for both pads to sit side by side without touching, and pads that overlap or make contact with each other prevent the electrical shock from reaching the heart properly.
Pediatric Pads vs. Adult Pads
Ideally, you’ll use pediatric AED pads with a pediatric attenuator, which reduces the energy the device delivers to a level appropriate for a small body. Some AED models switch to pediatric mode automatically when you plug in pediatric pads. Others require you to press a button or insert a special key to change from adult to pediatric settings. If you have access to an AED in your workplace, school, or home, it’s worth checking which type you have before an emergency.
If pediatric pads aren’t available, use adult pads. Both the American Heart Association and the American Red Cross confirm that adult pads are safe to use on infants when no pediatric option exists. The energy delivered (120 to 360 joules) exceeds the recommended dose for children under about 55 pounds, but there are reports of safe and effective AED use in infants even at those higher doses. In cardiac arrest, delivering a shock with adult pads is far better than not defibrillating at all.
Step-by-Step Pad Placement
Once the AED is powered on, remove all clothing from the infant’s chest and back. If the skin is wet, wipe it dry quickly with a cloth or towel. Check for any medication patches on the skin. These can block the electrical current and cause small burns, so remove any patches with a gloved hand and wipe the area clean before applying the pads.
For the front-and-back method:
- Front pad: Place one pad on the center of the infant’s bare chest, over the breastbone.
- Back pad: Place the second pad on the center of the infant’s back, between the shoulder blades.
An alternative anteroposterior position, described in the 2025 AHA guidelines, places the front pad on the left side of the chest between the breastbone and the left nipple, with the back pad on the left side of the back next to the spine. Either version works. One pediatric study found no difference in outcomes between front-and-back placement and the standard side-by-side positioning used on adults.
The critical rule is that the pads must not touch each other. The AHA specifies at least 1 to 2 centimeters of separation between pad edges. On an infant’s torso, front-and-back placement is almost always necessary to maintain that gap.
After the Pads Are On
Plug the pad connector cable into the AED if it isn’t already connected. The device will begin analyzing the infant’s heart rhythm. Before it does, make sure no one is touching the infant. Say “CLEAR” loudly so that bystanders step back. Any contact with the infant during analysis or shock delivery can interfere with the reading or injure the person touching them.
The AED will tell you whether a shock is advised. If it is, the device will prompt you to press the shock button. After the shock, immediately resume CPR. The AED will continue to guide you through cycles of analysis and CPR, typically re-analyzing the heart rhythm every two minutes.
Why Speed Matters More Than Perfection
The 2025 AHA and American Academy of Pediatrics guidelines stress attaching an AED as soon as one is available during infant cardiac arrest. Every minute without defibrillation in a shockable rhythm reduces the chance of survival. If you’re unsure whether you have the “right” pads or the “right” placement, use what you have. Adult pads on an infant in the front-and-back position will work. A slightly off-center pad will still deliver current to the heart. The only placement error that truly matters is allowing the two pads to touch each other, because that short-circuits the shock entirely.
If someone else is present, one person should perform CPR while the other prepares the AED. On a small infant, two-thumb chest compressions with hands wrapped around the torso are effective, and the rescuer doing compressions can briefly pause while pads are placed and the device analyzes. Minimizing pauses in compressions gives the infant the best chance.