Pacemaker & Defibrillator Implementation
What is an Implanted Pacemaker?
This small device is implanted under the skin and sends electrical signals to start or regulate a slow heartbeat. Implanted pacemakers are used to stimulate a patient’s heartbeat if the heart's natural pacemaker (the sinoatrial, or SA, node) is not functioning properly. It can also assist children who have an abnormally slow heart rate or rhythm, or if the electrical pathways are blocked.
Rhythm problems are common in teens and young adults with congenital heart disease due to changes in scar tissue resulting from prior surgeries and procedures.
Pacemakers may be placed under the skin in one of several locations. Young children (infants, toddler, preschool, and young school-aged children) often have the pacemaker generator placed in the abdomen, where fatty tissue can help protect the generator from normal everyday childhood activities. As a child nears adolescence, the generator is often placed in the shoulder area, just under the collarbone.
What is an Implantable Cardioverter Defibrillator (ICD)?
This small device is implanted in the skin (often in the shoulder area, just under the collarbone) and senses the rate and regularity of the heartbeat. When the heart rate goes too high, the ICD delivers a small, electrical shock to the heart to slow the heart rate. Many newer ICDs can also function as a pacemaker by pacing the heart out of a rapid rhythm and taking over when the heart rate is dangerously low. When the heartbeat becomes so erratic and disorganized that the heart muscle cannot pump blood from the ventricles, an ICD can deliver a stronger electrical pulse—often referred to as a "shock"—that can restore organized electrical activity, and therefore an effective heartbeat, to the ventricles.
What Happens During a Pacemaker and a Defibrillator Implantation?
Procedures to implant pacemakers or defibrillators are performed in the hospital, either as a short-stay surgical procedure, or in the cardiac catheterization or electrophysiology laboratory. Before the procedure, a child receives local anesthesia over the incision site and usually sedation to help them relax.
For older children and teenagers who receive a transvenous pacemaker, a small incision is made just under the collarbone. The pacemaker/ICD lead(s) is inserted into the heart through a blood vessel which runs under the collarbone. This procedure is usually performed in the catheterization laboratory.
In younger children, the pacemaker may be placed into the abdomen through a small incision. A second incision is made in the chest to visualize the heart. The lead(s) are guided to the heart, then placed on the heart's surface. This procedure is usually performed in the operating room. Once the procedure has been completed, the child goes through a recovery period of several hours and often is allowed to go home the day after the procedure.
What Happens After the Procedure?
After a child receives a pacemaker or ICD, the parents receive an identification card from the manufacturer that includes information about the child’s specific model of pacemaker, serial number and details on how the device works. Parents should carry this card with them at all times so the information is readily available whenever a health care professional examines and/or treats their child. In addition, the child can wear a medical identification bracelet or necklace to alert others about the pacemaker or ICD in case of emergency.
What Conditions Does it Treat?
When the heart's natural pacemaker (the network of heart tissues that conduct the electrical impulse downward from the atria to the ventricles) malfunctions, the signals sent out may become erratic — either too slow, too fast, or too irregular to stimulate adequate contractions of the heart chambers. When the heartbeat becomes erratic, it is referred to as an arrhythmia (an abnormal rhythm of the heart, which can cause the heart to pump less effectively).
ICDs may be recommended for children with significant ventricular rhythm problems that could pose a risk for sudden death. These rhythm problems are often associated with worsening heart failure.
Arrhythmias can cause problems with contractions of the heart chambers by:
- Not allowing the chambers to fill with an adequate amount of blood because the electrical signal is causing the heart to pump too fast.
- Not allowing a sufficient amount of blood to be pumped out to the body because the electrical signal is causing the heart to pump too slowly or too irregularly.