Technology is rapidly changing treatments that improve heart health. The following article will explore some of the cardiovascular implantable electronic devices that can be used in order to support a person with cardiac difficulties.
Pacemakers
A pacemaker is an electrically charged medical device.Your surgeon implants it under your skin to help manage irregular heartbeats called arrhythmias.
Modern pacemakers have two parts. One part, called the pulse generator, contains the battery and the electronics that control your heartbeat. The other part is one or more leads to send electrical signals to your heart. Leads are small wires that run from the pulse generator to your heart.
Pacemakers are used in both adults and children. Permanent cardiac pacemakers have been used in children for more than 30 years. These have become more widely used because of advances in pacemaker technology that allow greater customization of the pacemaker to the patient. The generators in these newer pacemakers have also become smaller and they last longer. Many aspects of pacemakers are similar between adults and children. The main difference would be in the choice of pacemaker and follow-up methods.
Implantable cardioverter defibrillators (ICDs)
Implantable cardioverter defibrillators (ICDs) are devices much like pacemakers that can pace and support the heart rate. An ICD differs from a pacemaker–it is a small battery-powered device placed in a person’s chest to monitor their heart rhythm and to detect irregular heartbeats. An ICD can deliver electric shocks via one or more wires connected to the heart to fix an abnormal heart rhythm.
A person might need an ICD if they have a dangerously fast heartbeat or a chaotic heartbeat that keeps their heart from supplying enough blood to the rest of their body. ICDs detect and stop abnormal heartbeats (arrhythmias). The device continuously monitors the heartbeat and delivers electrical pulses to restore a normal heart rhythm when necessary. An ICD shocks a person internally and automatically when it detects an abnormal heart rhythm. This is similar to how a paramedic would conduct CPR with a defibrillator.
An ICD is surgically placed under the skin, usually below the left collarbone. One or more flexible, insulated wires run from the ICD through the veins to the heart. Because the ICD constantly monitors for abnormal heart rhythms and instantly tries to correct them, it helps when a person’s heart stops beating (cardiac arrest), even when they are located far away from the nearest hospital.
When a person experiences a rapid heartbeat, the wires from the person’s heart to the device transmit signals to the ICD, which sends electrical pulses to regulate their heartbeat. Depending on the problem with their heartbeat, the ICD could be programmed for low-energy pacing where a person may feel nothing or a painless fluttering in their chest when their ICD responds to mild disruptions in their heartbeat. For more serious heart rhythm problems, the ICD may deliver a higher energy shock. This shock can be painful, possibly making the person feel as if they have been kicked in the chest. The pain usually lasts only a second, and there shouldn’t be discomfort after the shock ends.
Usually, only one shock is needed to restore a normal heartbeat. Sometimes, however, two or more shocks during a 24-hour period may be needed. Having three or more shocks in a short time period is known as an electrical or arrhythmia storm. This would indicate that the person should seek emergency care to see if their ICD is working properly or if they have a problem that could be making their heart beat abnormally.
If necessary, the ICD can be adjusted to reduce the number and frequency of shocks. A person may be prescribed additional medications to regulate their heart rate and to decrease the chance of an ICD storm. An ICD can also record the heart’s activity and variations in rhythm. This information helps the doctor to evaluate any heart rhythm problem and, if necessary, to reprogram the ICD.
Subcutaneous ICD (S-ICD)
A subcutaneous ICD (S-ICD) is a newer type of ICD available at some surgical centers. An S-ICD is implanted under the skin at the side of the chest below the armpit. It is attached to an electrode that runs along the breastbone.
A person with structural defects in their heart may be a candidate for this device as it prevents inserting wires to the heart through the blood vessels. Sometimes there are other reasons for avoiding ICDs. Implanting a subcutaneous ICD is less invasive than an ICD that attaches to the heart, but the device is larger in size than an ICD.
ICDs have become standard treatment for anyone who has survived cardiac arrest, and they are increasingly used in people at high risk of sudden cardiac arrest. An ICD lowers a person’s risk of sudden death from cardiac arrest more than medication alone.
