Pacemakers
A Pacemaker is a small computerized device implanted in the body to take over some or all of the functions of your own heart’s pacemaker and electrical system.
Why do I need a pacemaker?
Your doctor may have recommended a pacemaker for any of many reasons, usually related to your own pacemaker or wiring of your heart faltering either continuously or intermittently. This may be leading to dizziness, blackouts, poor heart rate response to activity leading to fatigue, reduced exercise capacity or breathlessness. Many of the electrical problems with the heart can be very intermittent. Pacemakers are not used to regulate heart rates that are too fast, although under circumstances requiring medication to control fast heart rates a pacemaker may be required to allow the use of such medications. More complex pacemakers, known at Biventricular devices, are also used to improve heart function even without any abnormality of the electrical system. Also, implantable cardiac defibrillators are pacemakers that also have the ability to detect and deal with life threatening disturbances of the heart rhythm.
What are the complications of a Pacemaker?
Overall pacemakers are relatively safe. Generally one can divide up the potential complications into three categories.
1. During the implant process, there is a risk when getting into the vein under the shoulder blade of puncturing the lung which lies very close to the vein, or an artery. This is not an uncommon occurrence but rarely leads to any ongoing problems, although very occasionally leads to partial collapse of the lung requiring aspiration of air form this area. This is a simple process. Whilst advancing and positioning the pacemaker leads, there is a very small risk (estimated at less than 1 in a 1000) of causing a small perforation in the heart. Similarly, this rarely causes any ongoing issues and is normally self limiting. Depending on the patient, there is a risk of bruising and bleeding, particularly if patients are on blood thinning medications, although again this is usually self limiting and can usually be dealt with at the time of the procedure.
2. Following successful pacemaker implantation, despite excellent lead positioning and contact with the heart, there remains an incidence of the leads moving such that either the next day or up to approximately one month, on testing they are no long in adequate contact with the heart. This is a nuisance and is easily dealt with by reopening the pacemaker implant and repositioning the pacemaker lead. The occurrence of this is very variable but is estimated to be between 5 and 10%.
3. The most feared complication of any pacemaker implant is infection and every precaution is made before, during and after the pacemaker implant of avoiding an infection. The incidence of this is extremely low but if the pacemaker or pacemaker leads do become infected then it is likely they will need to be removed.
How does a Pacemaker work?
Pacemakers are highly technical and complex devices with multiple different features. Essentially, the pacemaker is both a listening and a pacing device. Depending on the programmed settings of the pacemaker, the pacemaker will listen for your own heartbeat and listen to the movement of that heartbeat through the heart. If, after a programmed period, the pacemaker does not detect a correct heartbeat it will deliver an electrical impulse to the heart reproducing a heartbeat. Therefore, in many situations a pacemaker spends a lot of time listening without actually pacing the heart although in some patients the implanted pacemaker will be doing all the electrical pacing of the heart. Pacemakers these days are technically more advanced and are also taught to respond to patients’ activities, thereby reproducing the normal heart rate response to activity allowing patients to live normally.
How is a Pacemaker implanted?
Pacemakers are implanted either under local or general anaesthetic. Generally the procedure is fairly simple. Under sterile conditions, either on the right or the left, a small incision is made under the collar bone. Through this, the vein that leads directly to the heart is accessed and one or two pacemaker leads are put into this vein and advanced to particular parts of the heart, usually one in the atrium (top chamber) and one in the ventricle (bottom chamber). These leads will be carefully positioned and tested to ensure adequate positioning. The leads are then attached to the pacemaker “generator” and this is positioned underneath the skin through the small incision previously made. The wound is closed, usually with dissolvable stitches, and a dressing is applied. This process may take half an hour to 2 hours depending on different circumstances.
What to expect after the Pacemaker is implanted?
You will remain in hospital overnight and be discharged the next morning. It is likely you will have some discomfort in the area the pacemaker is placed and also some bruising is likely. A dressing will be placed over the wound and you should try and keep the area dry for about a week. For the first two weeks after pacemaker implantation you are not allowed to drive and should minimize use of the arm on the side that the pacemaker was implanted. You should avoid using the arm above shoulder level and try and avoid sleeping on the left hand side. Arrangements will be made to check the wound and repeat the pacemaker tests after about 2 weeks.
What is involved with Pacemaker follow up?
Once a successful pacemaker implantation has been performed an initial wound check is usually made 2-4 weeks later and the pacemaker is interrogated to ensure it is functioning normally. Once this has occurred, after approximately one month it is very unusual for the leads to move. Subsequent follow up usually occurs approximately every six months and takes approximately 5-10 minutes. A pacemaker technician will interrogate the device for any abnormalities that it may have detected, for the pacemaker settings to make any changes and to assess correct function and the status of the batteries. Depending on the pacemaker device itself and the positioning of the leads, most pacemaker batteries will last 5-10 years. Through regular follow up it is possible to accurately predict the life left in the battery and when appropriate arrangements will be made to change the pacemaker generator, which is a fairly simple process.