That’s a kind of pacemaker right?
Amazing how those have improved over time, now they are so small and long lasting.
Maybe more than you want to know, but ...
Not exactly. I'm on my third device.
The first one was strictly a defibrillator. It was implanted in 2007 and monitored my heart rate and if it got too fast, around 180 bpm, it would shock me. Hurts like hell but it got me back into rhythm. However, it didn't provide any ongoing pacing. EMTs have external versions of defibrillators, i.e., much larger because they have skin and tissue to penetrate ... "Stand clear".
After about 1.5 years I was having some problems and my cardiologist changed that first device out for a device that is both a defibrillator and a pacemaker in 2008. The pacemaker sends small electrical impulses to the heart in order to maintain a steady beat. In my case, the left side would get out of synch with the right side and the pacemaker helped with that. Again, if it detects fibrillation, it commands a defibrillating shock.
The pacemaker signals are small and I don't normally feel them. However, if I lie on my stomach, my diaphragm muscle starts to react to them and it feels uncomfortable - like hiccups. So, I don't lie on my stomach.
In 2019 my 2nd device was replaced by my 3rd device because the battery ran down (11+ years). This third device is also a combination pacemaker/defibrillator. The VA cardiologist who implanted it said it's the Mercedes-Benz of pacemakers.
All of these devices were/are about the same size, which is about the size of the palm of your hand. They have a specific shape in order to fit into the upper left chest cavity. However, devices are at times implanted into different areas of the body and may have a different shape. I don't know. All of mine have been implanted in the upper left chest and the shape has been the same. However, the combination pacemaker/defibrillator devices are thicker than the strictly defibrillator device.
All of these devices can be read and reprogrammed through the skin via radio signals and I periodically have it read. It records how many episodes of this or that which have been encountered. Normally, I don't have any significant events that are recorded and read except an occasional short episode of Atrial Fibrillation. The pacemaker tries to pace me back into rhythm.
One thing that is monitored closely is the battery life remaining. My first device was replaced after 1.5 years but not due to battery life. My second device lasted 11.5 years until the battery ran down. My third device was implanted in 2019 and the readouts say the device has another 6 year life span. I hope it (and me) last longer than that.
I also have machine at home that interrogates the pacemaker/defibrillator. It's placed near the bed and the interrogations occur in the middle of the night. I never know about them. After reading the device, the bedside machine sends the data somewhere using its own cell phone technology, but not via my cellphone.
All of these devices were implanted in a Cath lab. They require wires to be put into the inside of your heart and attach to the heart wall. They actually have little screw ends that are screwed into the heart muscle. Placement location is important. The first device had only one lead. The second device required three new leads to be implanted but the first one remained. I think for the 3rd device he was able to reuse to leads implanted with the 2nd device, but I'm not sure.
Maybe more than you wanted to know, but there it is.