Cardiac Pacemaker: Small Device with a Big Impact

We have become so accustomed to many medical achievements that we take their existence for granted: Artificial hip or knee joints, hearing or vision aids and also the pacemaker are normality for us today. Here you can find out exactly what a pacemaker is and when it is used.

What is a pacemaker?

A pacemaker helps the heart beat at its normal rhythm, which is appropriate for the situation. A modern pacemaker is barely larger than a matchbox, consists of a lithium iodide battery and sophisticated electronics, and has a titanium sheath. As a rule, a pacemaker weighs between 20 and 30 grams. It delivers electrical impulses to the heart tissue via one or more thin electrodes that are anchored in the heart to help the heart rhythm.

What is heart rhythm?

The heart is made up of muscle tissue that contracts (contracts) sequentially in a specific order, resulting in the movement of blood. We normally feel each regular contraction as a heartbeat. The conduction can be felt on the wrist as a pulse. The contraction and the heartbeat are normally controlled from a nerve point in the heart – the sinus node. From there, nerve fibers lead to all regions of the heart. As soon as the sinus node emits a nerve impulse, the nerve fibers cause the various heart chambers to contract and slacken so that the heart can perform its pumping function. However, this pumping function can only take place in a regulated manner if the nerves that influence the muscle tissue function and also respond to stresses such as climbing stairs or excitement.

Heartbeat irregularities

As people age, many experience heartbeat irregularities. For example, in sick sinus syndrome, when the sinus node delivers too few impulses, there is a decrease in heart rate (bradycardia). But the heart also beats irregularly or too infrequently if impulse transmission in the nerve pathways is disturbed – for example, due to circulatory disorders or nerve damage. For the person affected, this can manifest itself in unpleasant heart palpitations or dizziness attacks, which in their most extreme form can lead to unconsciousness (Morgagni-Stokes attack). Often, however, it “only” comes to an increasingly lower resilience: any effort, no matter how small, is difficult, one becomes increasingly limp and quickly gets out of breath.

When is a pacemaker inserted?

A pacemaker is always needed when the regulation of one’s heart rhythm is disturbed, the affected person shows the symptoms mentioned above, or it is to be expected that a life-threatening situation may occur due to the irregularity of the heartbeat. It must be clarified why exactly the heart rhythm is irregular: Is the sinus node no longer working properly, at which point is the transmission to the nerve fibers not correct, or is there another underlying disease (for example, a thyroid dysfunction) that affects the heartbeat? Medications for high blood pressure or heart failure can also be responsible for the arrhythmia. Long-term ECG and various other test methods can be used to stimulate the nerve fibers and check their function. Once the cause is determined, the appropriate pacemaker is selected.

What are the different types of pacemakers?

The type of pacemaker that is used depends on the nature of the condition. Depending on the rhythm disorder, electrodes are used to deliver impulses in one, two or even three chambers. The following types of pacemakers are common:

  • Single-chamber pacemaker: in this case, an electrode is inserted into the right main chamber or the atrium of the heart.
  • Dual-chamber pacemaker: one electrode leads into the right atrium and one into the right main chamber.
  • Three-chamber pacemaker: one electrode leads into the right atrium, one into the right main chamber and one into the left main chamber.

In addition, there is a still quite new type of pacemakers, namely so-called mini pacemakers. They are much smaller and weigh less than other pacemakers, only about two grams. They are wireless, but stimulate only one chamber of the heart.These “single-chamber” systems are therefore used less frequently than other pacemakers, for example, in patients with permanent atrial fibrillation.

New features of modern pacemakers

In addition, modern pacemakers are able to adapt their frequency to the wearer’s activity by means of sensors: Climbing stairs, running, working, and even excitement cause the heart rate to increase. Today, each pacemaker can telemetrically deliver its data to a data interface located outside the body, so that maintenance and control of the pacemaker have become relatively easy. So-called “home monitoring,” which sends data to a terminal outside of follow-up appointments and notifies the physician in the event of deviations from normal function, is already possible with some implants today.

How is a pacemaker inserted?

Today, a pacemaker is usually inserted in a short operation under local anesthesia. During this procedure, a pocket is prepared in the subcutaneous fatty tissue below the left or right collarbone and the pacemaker device is placed there. A larger vein runs under the collarbone in which the thin electrode can be advanced to the heart. Depending on the make, the electrode is screwed into place in the heart with a twisting motion or anchored by small barbs. It is then connected to the pacemaker. One can immediately test whether the pacemaker is working properly and sending impulses to the heart. If the model requires two or three electrodes, the same procedure is followed with the other electrodes.

How long does a pacemaker last?

While the first implanted pacemaker stopped working after just one day in 1958, the average battery life of modern pacemakers today is six to ten years. Unfortunately, it is not possible to replace only the batteries, as they are permanently connected to the device. Thanks to technical advances, it is possible to check how long the lithium iodide batteries will last during each pacemaker check. Even if the device signals that it will soon run out of power, this does not mean that a new device must be inserted immediately as an emergency. Today’s devices usually continue to operate for months without failure, so surgery can be well planned.

What does a pacemaker patient need to be aware of?

After surgery, the pacemaker is programmed to best fit the patient’s needs. The data will be entered in the pacemaker card that you will receive after implantation. Always carry it with you – this way, in case of unclear rhythm disturbances, it can be precisely checked whether your little helper is the trigger. Regardless of the pacemaker implantation, patients with atrial fibrillation should ideally limit their alcohol consumption. Regular or excessive alcohol consumption has been shown to promote atrial fibrillation.

Enhancing performance

Many patients feel an improvement in their performance. While you will still be physically limited by some soreness in the first few weeks after surgery, you will be able to return to almost any sport later on – though you should avoid martial arts and archery.

Be careful with electronic devices

Since pacemakers do not make any noise, your small additional device will eventually become more and more a matter of course for you. Still, you shouldn’t completely forget about it, especially around certain other electronic devices: Magnetic resonance tomographs, which generate a strong electromagnetic field, can influence your pacemaker in its function. Furthermore, pacemaker patients should exercise caution when handling the following devices:

  • Cell phones: Cell phones are usually no longer a problem for pacemaker patients. Nevertheless, with a cell phone but always a safe distance of about 15 to 20 centimeters to the pacemaker should be maintained.
  • Kitchen and household appliances: to machines such as toasters, stoves or the washing machine affected should not fall below a minimum distance of 15 to 30 centimeters. Information on the influence on your pacemaker you get in case of doubt about the manufacturer’s instructions.
  • Merchandise security systems: merchandise security systems,which are located in department stores in the entrance and exit area, can also temporarily interfere with the pacemaker. However, this phenomenon rarely occurs.

Devices for personal hygiene such as the razor, hair dryer or electric toothbrush, on the other hand, are safe for people with pacemakers.

Sources of danger with the pacemaker

Let your doctor inform you about possible sources of danger. Vacations and even airplane travel are no problem, but don’t forget your pacemaker ID card.In airports, your pacemaker can alert the metal detectors and then your ID card will help clear them up. Worries about sudden device failure are unnecessary with today’s models. During regular follow-up examinations, the function of the small but extremely powerful helper is checked. Rejoice in your electronic miracle device!

  • Online information of the University Hospital of Munich: pacemakers / defibrillators. (Retrieved: 06/2020)

  • Winter, S. et al / Ärzteblatt (2017): Wireless pacemakers: experiences and outlook. (Retrieved: 06/2020)

  • Internisten im Netz (2019): What can knock pacemakers out of sync. (Retrieved: 06/2020)

  • Pocket guideline of the German Society of Cardiology – Cardiovascular Research e.V. : ESC Pocket Guidelines. Pacemaker and cardiac resynchronization therapy. (Status: 2015)

  • Voskoboinik, A. et al (2016) : Alcohol and Atrial Fibrillation. A Sobering Review. In Journal of the American College of Cardiology, vol. 68(23), pp. 2567-2576.

  • Online information from the German Heart Foundation: be careful with pacemakers: how much distance to keep from electrical devices? (Retrieved: 06/2020)