Permanent Pacemakers are employed to ensure that the heart rate is not allowed to drop below definable limits. For most people, they are implanted because of symptomatic slow heart rhythms that have either resulted in dizzy spells or blackouts. In some cases, pacemakers are recommended because of a perceived high risk of having blackouts.
The normal heart beat is generated by a cluster of specialised cells high in the right atrium. This area is called the sinus node. Impulses emitted by this area spread in a wave through the uppre chambers causing them to contract. The electrical impulses then travel to the lower chambers through another specialised region known as the atrioventricular node. The signals are then split into two branches that rapidly transmit the signals through the left and right ventricles. The development of a slow heart rhythm can be due to failure of any or several parts of the conduction system. The nature of the conduction problem often influences the type of pacemaker that is chosen for patients.
How Are Pacemakers Implanted?
Pacemakers are implanted under local anaesthetic. The procedure usually takes less than one hour and it is usual to stay in hospital overnight after the procedure. The local anaesthetic is injected into the skin under the collarbone on the left side of the chest. A small incision is made in this region and the pacemaker leads are inserted into a vein through the incision. The leads are very floppy and flexible and slide down the vein until they are sitting in contact with the appropriate heart chamber(s). In most patients, alead is passed to both the upper and lower chambers. The ends of the leads are then plugged into the pacemaker box. This box is roughly the size of a gentleman's wristwatch. The wound is then closed with stitches that will dissolve over a few weeks.
How Do Pacemakers Work?
The basic technology is very simple. The leads in the heart detect the electrical heartbeat in the chamber(s) that they are situated. Provided signals are regularly detected and relayed to pacemaker box, the pacemaker will not do anything. However, if the time interval between beats is longer than the limit programmed into the pacemaker, the generator will send a signal down the leads to the heart stimulating it to beat. Similarly, if the pacemaker senses that the signals are not getting through from upper to lower chambers in time, an impulse is sent to the lower chambers telling them to contract in harmony with the upper chambers to maintain the maximum efficiency of the heart. Pacemakers have additional functions including the ability to sense physical activity and breathing rate. This enables the pacemaker to make the heart speed up or slow down according to the activity levels of the patient.
How Long Do Pacemakers Last?
This depends on how much work it is required to do and depends on many factors. If a patient's heart requires pacing all the time the battery may last 5 years or less. If the pacemkaer is rarely needed it may last twice as long. Many patients will require a generator change within their lifetime but this is usually even more straightforward than the original operation.
How Long Will I Need To Be Off Work?
Most patients can return to work after 7 days. If you have a very physical job, or one that is associated with a high risk or accidents or responsiblility for others, your employer may stipulate up to a month off work. The DVLA state that you are not allowed to drive for 7 days after a pacemaker implantation. For drivers with 'Group 2' entitlement such as HGV drivers, longer periods of disqualification apply.
How Often Will I Need to Come For Checkups?
After the initial operation, follow-up visits are usually arranged 2-4 weeks after the operation, then 3 months later and then it is usually only once a year until the battery begins to show signs of running low. Once this happens, you would usually be put on a list for routine replacement of the generator.