A pacemaker is a small, implanted medical device designed to regulate the heart’s electrical system. It generates electrical impulses delivered to heart chambers, ensuring the heart beats at a steady and appropriate rate. Pacemakers are often necessary when the heart’s natural rhythm is too slow, pauses frequently, or beats irregularly, a condition known as an arrhythmia. By stimulating the heart as needed, a pacemaker can prevent symptoms such as fainting, dizziness, and extreme tiredness, allowing individuals to maintain a more active life.
Problems with Leads
Issues with pacemaker leads, the thin wires connecting the pulse generator to the heart, are a common concern. One problem is lead dislodgement, where the lead moves from its intended position. This can lead to symptoms like dizziness, lightheadedness, an irregular heartbeat, or chest pain. If a lead dislodges, a chest X-ray can confirm the issue, and the lead may need repositioning or replacement.
Another issue is lead fracture, where the wire breaks. This can impair the pacemaker’s ability to deliver electrical signals or sense the heart’s activity. Symptoms might include a return of original heart rhythm problems, such as a slow heart rate.
Insulation breaks, involving damage to the protective coating around the lead, are also possible. These breaks can cause electrical currents to escape, leading to unintended stimulation of surrounding tissues or a loss of pacing or sensing. Mechanical stress from lead movement, material degradation, or manufacturing defects can cause insulation breaks. Abnormal lead impedance or an elevated pacing threshold can indicate an insulation defect.
Battery Life Concerns
Pacemakers are powered by batteries with a defined lifespan, typically 5 to 15 years. Battery longevity depends on factors such as the pacemaker type, its programming settings, and how frequently it delivers electrical impulses. When the battery nears depletion, the pacemaker provides warning signals rather than suddenly stopping.
Signs of impending battery failure can include irregular heartbeats, increased fatigue, dizziness, or fainting spells. These warnings allow for a planned replacement, usually several months before complete depletion. Battery replacement typically involves replacing the entire pulse generator, as the battery is sealed within the device. This procedure is often less complex than the initial implantation and can frequently be performed on an outpatient basis.
Risk of Infection
Infection is a serious complication that can occur after pacemaker implantation. Infections typically develop at the site where the device is implanted, or less commonly, they can spread to the leads and the heart itself. Most infections occur within the first 12 months following the procedure, often due to bacterial contamination during the surgery.
Signs of an infection at the implant site include redness, swelling, pain, warmth, drainage from the incision, or fever. If left untreated, a pacemaker infection can spread, potentially leading to serious conditions like pneumonia, endocarditis, or sepsis. Treatment usually involves antibiotics and, in many cases, complete removal of the infected device and leads, followed by implantation of a new system in a different location.
Device Malfunctions
Beyond issues with leads or battery, pacemakers can experience broader electronic or programming malfunctions. These include oversensing, where the pacemaker incorrectly detects electrical signals that are not true heartbeats, such as muscle activity or electrical interference. When oversensing occurs, the device may mistakenly inhibit pacing, leading to an inappropriately slow heart rate.
Conversely, undersensing happens when the pacemaker fails to detect the heart’s natural electrical activity. This can result in the pacemaker delivering unnecessary electrical impulses, potentially competing with the heart’s own rhythm.
Inappropriate pacing can also occur, meaning the device paces at the wrong rate or time. Such malfunctions can stem from programming issues, lead problems, or changes in the heart’s signals. These technical issues are typically identified during routine follow-up appointments, where the device’s performance is interrogated. Many malfunctions can be corrected by simply reprogramming the pacemaker’s settings. In rare instances, if reprogramming is not sufficient, replacement of the device may be necessary.