When pacemakers were first invented, there were large, heavy devices with lots of batteries and not much device longevity. In fact, one of the first pacemakers implanted in Sweden depleted its battery energy before the patient was discharged from the hospital. A replica of one of those old “hockey puck” devices is on the far left. (It’s done in clear epoxy so you can see the internal parts–the actual original old pacemakers had metal casings.)
Over the years, pacemakers got smaller and smaller. The downsizing trend shown here is only part of the journey. Today there are pacemakers that are very tiny (there is a system out there that is about the size of a quarter). And while the footprint was reduced, the capabilities of these system expanded.
First of all, battery technology evolved in a big (little) way so that very tiny lithium-iodide cells could power a pacemaker for a decade or longer. Device longevity depends on how much work the pacemaker has to do, but many years of reliable constant service are the norm.
In addition, pacemakers expanded their capabilities. Today, pacemakers can record intracardiac electrograms (like an ECG but taken from inside the heart rather than by electrodes on the outside of the body), store them in memory, and replay them as the clinician orders. Not only that, pacemakers are smart enough to identify triggering events, so they know what to record. For instance, some pacemakers allow you to program very high atrial rates as a trigger so that the doctor might be able to catch an intracardiac electrogram of atrial fibrillation. This can be very useful since atrial fibrillation is sometimes pretty sneaky and does not always show up when the patient is having a formal ECG at the doctor’s office.
Pacemakers have also automated a number of features so that programming is easier. Pacemaker are designed to fill in the missing beats in a patient’s cardiac rhythm. Since every patient is unique, pacemakers have to be individually programmed for optimal results. There are lots of adjustments that can be made so that the pacemaker interacts in the most effective way possible with the patient’s own heart. It used to be that these were all adjustments that had to be made individually by a clinician, who may have had to do some calculations to figure out the best settings. Today, many of these programmable features are automated so that the device automatically regulates itself to the best settings. (Of course, the clinician can override these settings, if necessary–but usually it’s not necessary.)
Why are smaller pacemakers better? Mainly, they are much more comfortable. These devices are worn inside the body, and the most comfortable “fit” involves rounded corners, light weight, and a small, very thin system.
Pacemakers have evolved considerably over the decades and they are manufactured by several companies, each of which makes multiple devices. Because systems can last a long time, pacemaker technicians need to be prepared to know the programming nuances of many different devices. That’s why a systematic study of pacemakers is so crucial for device specialists. If you think you’d like to be part of the pacemaker industry, there is no better way than to join our class. We start in January and by next summer, you could be embarking on a whole new career and helping patients! Want to know more? Call me at 713-486-1636. There’s no obligation to you–clearly, this is not a career for everyone but if you think it might be the place where you could make your best contribution, call me today!