Will My Child Need a Pacemaker After CAVSD Repair?

A complete atrioventricular septal defect (CAVSD) is a condition where there is a large hole in the center of the heart affecting all four chambers, and the heart has one large common valve instead of two separate ones. It is very common for parents to worry about their child needing a pacemaker after surgery to repair this defect. Fortunately, the risk of needing a permanent pacemaker is low. Only about 1% to 5% of children require a pacemaker after CAVSD repair ^[1][2]. When a pacemaker is needed, it is usually because the heart’s electrical system was injured during surgery, causing a condition known as complete heart block ^[2]. If your child does need a pacemaker, modern devices are highly reliable and will allow them to live a normal, active life.

Why is the electrical system at risk during CAVSD surgery?

To understand why a pacemaker might be needed, it helps to look at the unique anatomy of a heart with a CAVSD. The heart has its own internal electrical wiring that tells it when to beat. A key part of this system is the AV node, which acts as a relay station between the upper and lower chambers of the heart.

In a structurally normal heart, the AV node sits in a safe, predictable spot. However, in a child with a CAVSD, the AV node is shifted downward and backward toward the bottom edge of the heart’s dividing wall ^[3]. Additionally, the specialized nerve fibers that carry the electrical signals (the Bundle of His) run directly along the rim of the hole between the lower chambers (the ventricular septum) ^[3].

During surgery, the surgeon must sew patches directly over the holes to separate the heart’s chambers. Because the electrical pathways run right along the edges of the holes, the surgeon has to place stitches extremely close to the conduction system ^[4][5]. Even with careful, precise surgical techniques, the electrical tissues can be bruised, stretched, or inadvertently caught in a stitch, leading to heart block ^[4][5]. Children with Down syndrome (Trisomy 21), which is frequently associated with CAVSD, have a slightly higher risk of requiring a permanent pacemaker after surgery ^[6].

What happens if the electrical system is damaged?

If the electrical pathways are injured, the signals from the top of the heart cannot reach the bottom chambers. This is called complete heart block ^[2][1]. Without these signals, the heart beats too slowly to pump enough blood to the body.

However, this damage is often temporary, caused by swelling or bruising around the stitches. To manage this safely, surgeons routinely leave temporary pacing wires attached to the heart during the operation ^[7]. While your child recovers in the ICU, these temporary wires can be connected to an external machine to keep their heart beating at a normal rate.

The care team will typically wait 7 to 10 days to see if the swelling goes down and the heart’s natural electrical rhythm recovers ^[8][9]. If the electrical system does not recover after this waiting period, the heart block is considered permanent ^[8]. At that point, a permanent pacemaker is surgically implanted to send regular electrical impulses and keep the heart beating safely ^[1].

Life with a pediatric pacemaker

Hearing that your child might need a pacemaker can be frightening, but it does not mean they will have a fragile life. However, it does require some ongoing medical care and adjustments. If a permanent pacemaker is required, here is what you can expect:

• Placement in babies and toddlers: In small children, the pacemaker generator (the battery pack) is typically placed in the abdomen rather than the chest, and the wires (leads) are attached to the outside surface of the heart (epicardial pacing) ^[10]. As your child grows taller, they will eventually require surgeries to lengthen or replace the wires so they don’t pull tightly on the heart ^[11][12].
• Battery replacements: A pacemaker battery usually lasts between 5 to 10 years, depending on how often your child’s heart relies on it ^[13]. When the battery runs low, your child will need a relatively minor surgery to replace the generator unit.
• Active lifestyles and sports: Children with pacemakers can still play, run, and participate in most activities. Tailored exercise programs can help build stamina ^[14]. For activities with a risk of hard impact to the chest or abdomen (like certain contact sports), your child can wear specialized padded protective gear over the pacemaker site ^[15]. This simple precaution dramatically lowers the risk of device damage ^[15].
• Safety and technology: Modern pacemakers are well-protected. Most new devices are “MRI-conditional,” meaning your child can still have MRI scans safely under specific medical protocols ^[16]. For airport security and other metal detectors, you will carry a medical ID card for your child so they can be screened safely without setting off alarms or risking interference ^[16].

The goal of CAVSD surgery—and of a pacemaker, if one is needed—is to give your child the opportunity to thrive and live a full, active life.