Key dates
Pacemaker firsts
1958
1960
1975
The first battery-driven pacemaker is used, but the pulse generator is an external box which the patient wears.
Two years later, the world’s first fully internal pacemaker is implanted in Uruguay.
The first lithium battery is introduced, greatly prolonging the life span of pacemakers.
2009 In New York a Wi-Fi-enabled pacemaker is implanted, which can communicate with the patient’s doctor daily.
2011 Medtronic makes a tiny pacemaker the size of a Tic Tac. It is currently undergoing research.
dId yOU KNOW? Pacemakers are classified based on the number of heart chambers that they ‘pace’
How pacemakers work
Learn how these cutting-edge devices are giving tired hearts a new lease of life The heart has a natural pacemaker called the sinoatrial node. This fires electrical impulses which regulate our heartbeat. Certain conditions cause this natural pacemaker to malfunction though, which is where artificial pacemakers come into play. There are several different types of artificial pacemaker, each suited to certain conditions. For those with irregular or very slow heartbeats, a permanent pacing device will send out an impulse to control every single beat. For those who have occasional problems, meanwhile, a responsive pacemaker will take over only when it detects irregular cardiac rhythms. The power supply for artificial pacemakers needs to be long-lasting and reliable. The most commonly used type is a lithium battery, which has been proven to last for ten years. At that stage they won’t suddenly cut out, as specialist equipment can detect those low on power in plenty of time. They can then be swapped out for a new one in a second minor procedure.
electrode connector box
electrodes Either one or two wires are connected here, which are then carefully placed into position inside the heart.
Fine wire electrodes run from this box to the chambers of the heart, which transmit the electrical impulse that control its rate.
Pulse generator case This small box, about 4cm (1.6in) wide, is implanted under the skin near the patient’s left shoulder. It is made of a biocompatible metal such as titanium.
A pacemaker is implanted as a day-case procedure under a local anaesthetic. The pacemaker box is put just beneath the skin in the upper left-hand corner of the chest; they can easily be felt in those fitted with them. The main environments people with pacemakers should avoid are those with strong magnets, which can affect the pacing capability and also the position of the machine. This means steering clear of MRI scanners and certain electric motors, which generate electromagnetic fields. Microwaves and airport security gates are perfectly safe, and certain modern pacemakers are even designed to be MRI compatible too.
circuitry These circuits (formed from switches, microprocessors and amplifiers) generate the pulse at a predetermined rate, or can also fire the pacemaker on an ‘as-needed’ basis.
Battery The sealed lithium iodine battery can last for up to a decade, and generates the energy for each paced impulse sent to the organ.
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Pacemaker aftercare
