Pacemakers: Keeping Our Hearts Beating

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We almost never notice the beating of our hearts until something goes wrong. Luckily, physicians and scientists developed pacemakers to keep our hearts beating. This is the story and some of the science behind this revolutionary medical device.

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The Story And Science Behind The Pacemaker

Our cells are specialized to conduct electrical currents. There are many elements in our bodies, such as sodium, magnesium, calcium and potassium that have a specific charge. These are called ions and they are used to generate electricity.

The human body relies on electricity to perform many of the functions that keep us alive.  Electricity is required for the nervous system to send signals all throughout the body. One thing this does is send electric signals to the heart to make it beat faster or slower.

The beating of the heart is regulated by electricity and that keeps us alive. Without this regulation, the chance of survival is slim to none. So, everything is fine when we are healthy, but what happens when something goes wrong with these electrical impulses to the heart?

Today, we’re going to learn about how the work of many scientists and physicians culminated to give us an amazing device called the artificial pacemaker to keep our hearts pumping regularly.

HEart pulse ekg.jpg

 How The Body Creates Electricity

 So, like we said earlier, cells are specialized to conduct electricity. It’s pretty complex, but here’s a somewhat simple explanation of how the process works.

Cells are typically a bit negative overall in terms of their charge because they have more potassium ions inside than sodium. Potassium ions are negative and sodium are positive. The sodium ions concentrate outside the cell membrane, begging to get in to balance the charge.

However, the cells won’t just let the sodium in for no reason. There is no free lunch in the world of a sodium ion. Instead, the cell will wait until the body needs to send a message and then opens the sodium-potassium gate to let some lucky sodium ions in.

When this gate opens, sodium tries to rush in to balance the charge and at the same time, potassium rushes out. The universe wants the charge to be as balanced as possible to come to some sort of equilibrium.

Now, when these two ions change places, the concentration of the charges changes and this makes the cell increasingly positive. Once the positive charge gets high enough, the cell will discharge the sodium, and the same process will rapidly take place in the cells next to it. This is a flow of charges and creates a form of chemical electricity.

This chain reaction is highly controlled by cells and nerves and sends specific messages throughout the body. It may be a pain signal, a signal telling you your skin is hot or cold, or maybe the movement of a muscle.

The heart gets electrical signals from the brain to contract and release which pumps blood throughout the body depending on how much is needed. When blood needs to be pumped, faster electrical pulses are sent.

This is a good visual and explanation of how the body creates electricity and also how it controls the heart!

The human body in total produces between 10-100 millivolts. That’s a lot right? Milli kind of sounds like million… Well, it’s actually not that much. It would take about 70 hours to charge a smartphone and an electric eel produces 600 volts. That’s 6000 times more than our body. But hey, it does the job.

The human body is really amazing. There are so many processes that use different forms of chemistry to keep us alive. It’s that complexity and mystery that made me study biochemistry. I wanted to know how chemistry makes life function.

Really, most science is awesome, which is why I started this podcast. There is so much to learn and it’s all fascinating.

 The Heart’s Electricity System Doesn’t Always Work Well

Anyways, back to the story. The body in all it’s glory doesn’t always work the way it should which is why we see disease and eventually die I guess. That’s a bit morbid, but if the body was truly perfect, it wouldn’t break down over time.

One of the ways that the body can malfunction is with those electrical signals to the heart. The SA node is the part of the heart the receives the electrical signal from the brain and tells the rest of the heart to contract. If that part goes bad, you can start to have some pretty serious heart problems.

These can range from small heart palpitations or flutters to more complicated problems like extreme lack of blood flow which can lead people to become oxygen deprived or have a stroke. This is especially harmful if the person already has coronary heart disease where the blood vessel tighten which makes it even harder for blood to flow.

Discovering The Role Of Electricity In The Heart

Unfortunately, for people who had these types of heart problems way back in the past, nothing could be done for them for much of history. After all, it wasn’t until the late 1700’s that physicians even found out the heart worked by using electricity.

Interestingly, a Danish physicist named Nikolev Abildgaard was the first in recorded history to experiment with the effect of electricity on the body. He hooked up a chicken’s head with electrodes and gave it a shock that killed it.

The stimulation device used by Nikolev Albidgaard.   Credit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3232561/

The stimulation device used by Nikolev Albidgaard.

Credit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3232561/

He then applied other shocks to different parts of the body and nothing happened until the electrodes were placed on the hen’s chest. The chicken miraculously rose from the dead and walked away. This was the chicken’s lucky day and it was the first “patient” to receive defibrillation.

Unfortunately, even though this was a groundbreaking discovery, there was no context to put it in so the researcher had no idea why this happened. He thought that he created some sort of chicken zombie. I wonder if it was at that point that the scientist started to plot out his plan for world domination using an army of chicken zombies.

Electricity Is Inherent In All Tissue

In 1791, an Italian physician and scientists named Luigi Galvani was the first to say that electricity is inherent in all tissue. He ran experiments where electrodes were hooked up to frog muscles, making them contract when electricity was pulsed. It was also generally agreed upon now that electricity was crucial for the heart.

Here’s a funny story I came across in my research. A scientist named Alexander von Humboldt found a dead bird in his garden and put a piece of zinc in its beak and a piece of silver in the bird’s rectum. After a shock was applied, the bird flapped its wings.

That’s not the funny part. Rumor has it that Alexander tried the same experiment on himself and had some not so desired results. Hey, I’m not here to judge what he did in his spare time. All in the name of science.

During the French Revolution in the early 1800’s, there was no shortage of decapitated human bodies for scientists to experiment on. They noticed the heart would beat with an applied electric current, though there was no practical use for it.

Using Electricity to Stimulate The Heart

Let’s jump to 1872. It was in this year that a child was the first person to be resuscitated after drowning. A physician attached an electrode to the child’s leg and pulsed electricity and miraculously, the child came back to life. I’m not sure if the physician knew to do this or if it was a dark science experiment, but either way it worked.

It was around the late 1800’s that scientists started to experiment a bit deeper with the effect electricity had on the heart. In 1882, an unskilled worker had a tumor removed from her chest which exposed her heart. Well, if you’re already in there, why not do a quick experiment, right?

So, an immoral scientist named Hugo Von Ziemssen started stimulating the patient’s heart with electricity and found that he could actually control the beat of her heart based off the electrical pulse. This definitely would not pass the ethics committees we have today, but back then it was kind of a free-for-all.

This is the cardiac activity from the experiment. The arrows indicate where stimulation started.   Credit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3232561/

This is the cardiac activity from the experiment. The arrows indicate where stimulation started.

Credit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3232561/

Also around this time, an English doctor named John Mac William collected and analyzed tons of data on the beating of the human heart and determined the pace or rhythm. He was also the first to start to systematize applying electrical pulses to the heart to make it beat.

Despite these advances surrounding the role of electricity in the heart, there were no effective treatment options and we would have to wait about 20-30 years until we would start to see this research put to use.

Early Techniques For Starting a Stopped Heart

There were some pretty horrendous techniques that were used to try and get the heart to start beating again when patient’s hearts stopped. The technical name for one technique was “mechanical stimulation of the heart” and “intracardial therapy.” I’m not sure about you, but no part of ‘mechanical stimulation of the heart’ sounds pleasant to me.

Well, after learning more about them, they are much more unpleasant than they sounded. In some cases, the patient would be put under anesthesia, and a needle would be inserted through the chest into the heart. The physician would then squeeze some adrenaline mixed with other compounds like caffeine into the heart in an attempt to start it up again.

However, this method was very inefficient and would only work about 25% of the time. The view of many at the time was that it was an unnecessary brutality that was unneeded at the end of a patients life.

heart beat.gif

Here is a letter to the editor written to the Journal of the American Medical Association regarding a paper that was published on the subject in 1930:

“Even if the heart gives one beat under the stimulus of a puncture, it will not give another unless a second pin is stuck in; and then a third, a fourth, and so on; or unless one pin is repeatedly withdrawn and thrust in again. A mere stimulus by a pin prick does not move any blood and does not counteract the asphyxia of the heart muscle. It is therefore far less effective than squeezing the heart through the diaphragm.”

I think he is advocating for the use of CPR, which isn’t as brutal but can sometimes result in broken ribs and is still not very effective. In addition to the needle, they would also sometimes directly squeeze or pinch the heart to stimulate it if the patient was in surgery and their heart stopped.

I don’t know about you, but none of these methods seem to work very well and all are pretty brutal. The low efficiency and lack of any solution was probably very frustrating and discouraging for physicians and patients. Here is another quote from a physician in 1932 talking about the bleak outlook of the time:

“The more or less dramatic events attending cardiac arrest, whether the scene be laid in a well-appointed hospital operation amphitheatre, a doctor’s consulting room or in less favorable circumstances are always associated with ill-defined attempts to do something to restore cardiac function. In the brief interval before complete surrender to death has taken place and before utter helplessness has seized those administering to the dying person, many random and badly executed procedures are invoked with the last minute hope of resuscitating the stopped heart” 1 . - Albert S. Hyman, New York, 1932

First Ideas For Keeping The Heart Going With Electricity

Physicians of the time were overwhelmed. They needed a way to make the hearts of patients functionally properly in order to do their job. But they couldn’t. All they could do up to this point was inject patients with adrenaline to try and boost their heartrate and press on the patient’s heart.

However, there were some ideas starting to pop up about ways to help people with heart problems. Interestingly, two doctors at almost the same time on opposite ends of the world came up with a solution.

In 1928 an Australian anesthesiologist named Mark Lidwell sort of just put together a procedure using the research we talked about earlier and stimulated the heart electrically, but included an actual rhythm with the applied electricity to produce a beat. Using this, he actually saved a baby that had a heart attack when it died.

The First Pacemaker

Then, the same American doctor who wrote that last quote named Albert Hyman made some crucial observations while using the needle method. He noticed that what matter much more than the substance in the syringe was the location and number of the pricks.

What he found was that the prick of the needle sort of was able to stimulate the heart by producing a path for electricity to flow. Inserting the needles changed the electric potential. From this, he got the idea to directly stimulate the heart using electricity with repeated pulses.

In 1932, he came out with what is generally referred to as the first artificial pacemaker. He made a generator that would produce direct power to two electrodes. Two large magnets were used to create a flux in the electricity and then there was a crank handle that would provide energy to the generator. The electrical current would then be controlled by how fast you cranked.

Albert Hyman’s first artificial pacemaker.   Credit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3232561/

Albert Hyman’s first artificial pacemaker.

Credit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3232561/

This was really a pretty impressive invention for the time. There were also measures in place to control the duration of the pulses as well so it wouldn’t just be one long electrical shock. The entire contraption weighed about 18 lbs, so there’s no way this was a long-term solution for a person’s heart problem. Also, imagine having to crank a handle all the time just to have your heart beat.

Hyman had a hard time finding buyers for his device and even a hard time finding someone to manufacture it. The Navy finally accepted a few in World War II in a last ditch effort to try and revive soldiers that were dying. This device was never thought of as being a tool for people with heart problems, but rather for stillborn babies and people who had sudden cardiac arrest.

Despite the ingenuity of the device, there were too many shortcomings and medical researchers of the tie determined that it was effective enough to be put into practice. It was also seen as sort of unethical to interfere with the natural process of the body. Hyman was sent off with his tail between his legs and his work was largely forgotten.  

The Pacemaker Gets An Overhaul

We will again have to wait a little while for any more progress. Sometimes, science is a little slower than we would like. Fast forward to after the Second World War in 1952 and let’s go to the University of Toronto in Canada.

Physicians were doing experiments on how to slow the body’s metabolism by cooling so that they could stop the heart for surgery. They found that when the patient’s heart would start up again, in order to keep them alive the rate of their heart would need to be controlled.

 To perfect their technique, doctors were operating on dogs when one day, a dog’s heart stopped. Out of curiosity, one surgeon named Wilfred Bigelow decided to poke the dog’s heart with an electric probe. The dogs heart started right back up.

Because of this and the problems they were having with hearts, engineers started to try and make a new and improved artificial pacemaker. They made a device that was similar in principle to Hyman’s first pacemaker, but it was upgraded in just about every way. It used a different generator, and electrical system among others.

This was a pretty cool contraption. You could alter pulse rate, voltage, and pulse duration. They also figured out a way to hook electrodes to the heart and then close the patient so that it could be used for regular use without much discomfort.

This was their finished pacemaker control device.   Credit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3232561/

This was their finished pacemaker control device.

Credit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3232561/

They had found a solution to not just their own solution when bodies were warming up after surgery, but also a much bigger, more general problem. This was that their device could be used all the time with bodies at normal temperature. However, their device failed where Hyman’s didn’t. Theirs couldn’t bring a heart back to life after stopping from cardiac arrest.

Although it didn’t work for bringing people back to life, it worked very well for when the heart was just barely operating. This is because it only stimulated the electrical center that told the heart when to beat instead of the entire heart.

The First Pacemaker Used In A Clinical Setting (Rather Than Experimental)

In 1952, science saw the first time that a pacemaker was used in a clinical setting. In 1952, a 75-year old man came into the Boston Beth Israel Hospital after having two Stokes-Adams attacks. That means he passed out due to his heartbeat being too weak. He also had heart block, which is a condition where your heart fails to pump properly.

In a 4 hour period, this man took 36 needles to the heart with adrenaline using the heart poking technique we talked about earlier. That does NOT sound like a fun time. It was worth it if it meant saving his life though. Unfortunately, these were ineffective and his condition deteriorated.

In a final effort, the attending physician named Dr. Zoll used an external electric stimulator that had the same type of generator as the previous pacemaker and restored the patient to a regular heart rate for about 25 minutes. Despite the success, the patient’s heart was too damaged from all the punctures before and he passed away.

However, this was very promising. In a similar manner, Zoll kept a 65-year old man’s heart going for 5 days using the same external electric stimulation. On the fifth day, the patient was actually discharged. Zoll was really onto something here. These shocks were incredibly fast. They lasted for about 2ms and would be sent 25-60 times per hour.

Here is a video of Dr. Zoll’s first patient. It’s so interesting seeing this old footage!

Zoll became a pioneer for practical and effective pacemaker use. He also realized that it was hard to tell when cardiac arrest occurred in patients under anesthesia so he made a device that could monitor heartbeat and then utilized the external stimulation if the heart stopped.

With this information, other physician scientists came up with an external pacemaker system that would automatically kick on if the heartbeat of a patient stopped in 1956. I had no idea that technology had this much capability all the way back in 1956.

While this was a big step, we sort of came back to it being used in cardiac arrest situations. It wasn’t feasible to have external stimulation like this over a long timeframe because being shocked on the chest isn’t fun and could be quite painful. Also, the electrodes had to be placed very precisely and ulcers would form under the electrodes after about a day.

The Golden Years of Pacemaker Development

The late 1950’s through the early 1960’s are known to be the Golden Years of pacemaking technology. Huge advances were about to be made. In 1957, an electrical engineer and TV repair person named Earl Bakken went on to make the first battery operated pacemaker and eventually went on to co-found the medical device company called Medtronic.

He co-founded the company in Minnesota with his brother-in-law Palmer Hermundslie worked out of their garage in northwest Minneapolis with colleagues at the University of Minnesota. I’m glad my home state of Minnesota finally made it into one of my episodes. This state is cold and doesn’t get a lot of love.

Anyways, they discovered that they could use a pulse genetator that was battery powered to send an electric shock through wires that were directly inserted into the hear of a dog. I’m not sure why they are experimenting on dogs so much. I’m also not sure where I stand on this morally. On the one hand, I don’t want the dogs to suffer, but on the other pacemakers have saved so many lives. Let me know what you think in the comments.

With their device, they were able to directly control the heartrates of the dogs. They insulated a wire all the way until the point where it was placed inside the wall of the right ventricle. The insulated portion was brought out the chest wall and connected to the negative terminal of the device. The positive terminal was attached to the skin near the top of the heart.

Medtronic’s first building. Of course, there’s snow on the ground.   Credit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3232561/

Medtronic’s first building. Of course, there’s snow on the ground.

Credit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3232561/

On January 30, 1957, a scientist named Walton Lillehei from the University of Minnesota team used the technique to pace the heart of the first human patient. It was a child who had heart block or a weak heart beat after surgery to fix a heart defect.

Instead of sending the wire directly through the wall of the chest, they found a way to send the wire through the veins. This proved to not only work, but with the advanced technology, the voltage was much lower than earlier models so the sensation wasn’t too painful.

Switching Over To Battery Powered Pacemakers

These devices weren’t using batteries yet, but a winter storm in the forecast would change all of that. Interestingly, this podcast is randomly set to come out on the day their pacemaker was first used in the child. I say that because that means it’s the end of January and a snowstorm like the one that was about to hit the University of Minnesota is about to hit tomorrow.

Back in 1957, there were no generators at the hospital and a snowstorm knocked out the power. The patients, mostly children, would lose their pacemakers if nothing was done. Lillehei heroically scrambled  to Earl and Bakken for the batteries they were developing for pacemakers at their new company, Medtronic.

They quickly went to work and pieced together a battery system using spare parts they had lying around along with parts that they tore out of other devices to make a battery backup that was just a little bigger than a deck of cards. In about 2 weeks, they had their solution.

This was tested in the University of Minnesota’s labs and the next day, it was tested on a patient with heart block. Instantaneously, the child’s heart returned to a regular rate. It was an instant success. The patient was actually able to come off of the pacemaker after a couple days.

Not only was the pacemaker generator and powersource small, but much safer than the wall plugin alternative. Here’s what Dr. Lillehei had to say about had to say about the advantages:

“Its small size, light weight, and self-contained power source allow for complete patient mobility……Because it is battery operated, patient safety and efficiency of patient care are greatly improved. The patient is not in danger of electrocution should a short circuit develop, as he is with equipment operating with alternating current, nor is he at the mercy of a power line failure or an accidentally pulled power cord”

An early battery powered pacemaker.  Credit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3232561/

An early battery powered pacemaker.

Credit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3232561/

Pacemakers Are Starting To Make An Impact

This technology started to be used more widely and was really starting to make an impact. Patients with major heart conditions were seeing big improvements in their conditions. In this early stage, the invention was already changing lives. There was a lot of potential here.

There were fears that clotting would eventually occur with a wire going through veins to get the wire to the heart, but anti-coagulants or blood thinners were used and this was never observed. The system was working well, but it wasn’t effective every time.

In a study at Montfiere hospital, 15 patients were treated with the wall-powered pacemaker but only 5 survived. Of the 10 deaths, 3 were caused because there were small electrical leaks that caused the heart to actually malfunction. That was kind of counterproductive. In another death, the pacemaker simply didn’t work for the patient.

Another died from an infection from the insertion. One more died from the wire actually making too big of a hole in the heart and finally, one patient refused to take blood thinners so they got a clot. Of you’re going to take the steps to have a wire passed through your veins to your hear and give all the control of your heart rate over to an outside electrical pulse, why would you reject blood thinners?

It was also found that if the pacemaker was used continuously long-term, the effectiveness would go down over time. This study really helped illuminate the problems with the current model of the pacemaker and scientists got to work fixing the problems. They completely got rid of the wall powered model and opted for the battery version to avoid the energy leaks that killed 5 people in the study.

Pacemakers Continue to Improve

Then, to avoid the issues associated with passing a wire through, they switched the location the wire was inserted so that it wouldn’t move as much to avoid damage. It was initially passed through the arm, but the arm moves a lot which could cause damage, so they switched to the jugular. Use was also switched from constant to a more need-based system so that a tolerance wouldn’t be built up.

These improvements were great, but this technology was rapidly changing into better and better forms. This seems to be getting a bit muddy at least, so let’s recap what’s been going on.

old%2Bhospital%2Broom.jpg

Scientists and physicians are controlling the heart beat in patients who either have gone through cardiac arrest or have a irregular heartbeat. In the cardiac arrest case, you can just apply a short-term electrical pulse to get it started again. It’s a little more complicated when it comes to the second case though.

So far, improvements were being made so that the device could be used long-term. They were making the power source more reliable and portable with the use of the Medtronic battery system. The delivery system was also being worked on. Instead of going straight through the chest, they were inserting a wire through veins and then finding which veins work best.

They made changes in all of these areas and came out with a device were you would strap the battery to yourself and it worked pretty well, but there was still a high risk of getting infections. Because of this, the only logical step was to make a system that was implantable so wires would have to leave the body.

 The First Implanted Pacemaker

Inspired by the work of Lillehei, Scientists got to work right away in Octoeber 1958. A surgeon named Ake Senning and an engineer named Rune Elmqvist out of Sweden started to experiment. They made a battery powered device that was encased and sealed so that it wouldn’t break down inside the body.

Interestingly, a woman came into the hospital labs and pressured them to test their device on her husband who was struggling from Stokes-Adams attacks. Remember, that’s where someone passes out from their heartbeat being too weak.

They knew it would be risky, so they performed the operation in the evening when there weren’t going to be any other operations. They didn’t want any publicity. They opened the patient up, stuck the wires in the myocardium and ran them to the battery unit that was placed inside the abdomen.

Senning accidentally damaged the apparatus while implanting it and had to do an emergency operation in the morning with their only other unit. Here is his account:

“On the 8th October 1958, in the evening, when there were no extra people in the theatre, I implanted the first pacemaker, but it lasted only 8 hours. Presumably, I had damaged the output transistor or capacitance with the catheter and I did not have the other one which was in the lab. I implanted the other one early the next morning”. Senning then concludes: “In the 1950's we did not have any liability problems. The patient and relatives were happy if the patient survived.”

The first implanted pacemaker.  Credit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3232561/

The first implanted pacemaker.

Credit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3232561/

It makes sense I guess. The patients were just trying to survive in a bleak time when there weren’t many options. Luckily, the second pacemaker worked well and this was the first implanted pacemaker. However, it stopped working after about a week. Fortunately, his condition didn’t make a comeback until the technology had advanced.

They used a nickel-cadmium rechargeable battery because at the time it was thought to be the most reliable and healthy option. Healthy was important because many of the batteries of the time were toxic.

Here’s a part of the story that was crazy. They used wireless charging to recharge the batteries. Again, I had no idea that they would have this technology in 1958. In a nutshell, they had an antenna attached to the battery and then would beam a 150 kHz radio wave at it that would charge it. This was done once a week for 12 hours each time.

The engineering and innovation here was amazing. These devices were completely handmade. They even used shoe polish cans as a mould for the device. Right now we are seeing what is the base for the technology as a whole.

Implantable Pacemakers Were The Way Of The Future

Improvements kept being made in the electrical system to make it more reliable and efficient as well as the batteries being improved so that they lasted longer. Shortly after this, an improved system was made and a system started to be clinically used and tested.

One of the scientists working on it said “I seriously doubt if anything I ever do will give me the elation I felt that day when a 2 cubic inch electronic device of my own design controlled a living heart.” That’s understandable. I really wonder what that would feel like.

The wire system leading to the heart was improved as well so that it was more reliable and a tolerance wouldn’t build up. It was thought that the tolerance came from a build-up of scar tissue. One way they did this was by making a wire that would excrete a steroid to reduce inflammation and decrease scar tissue. They also made the wire more flexible so that it wouldn’t become dislodged.

Nuclear energy was majorly considered in the 1970s to power pacemakers. The energy source would last 10-20 years and was very reliable, but it would release radiation. However, the amount of radiation was pretty small. Lithium ion batteries came along before the nuclear option caught wind and replaced it. It lasted as long but didn’t emit radiation.

Pacemakers Can Respond to the Patient’s Activity Levels And More

Then, Medtronic came out with a model that allowed the user to switch between 70 or 100 beats per minute using a magnet to flip a switch. This was super important because during activity, the low pre-set wouldn’t pump fast enough if the patient was doing any physical activity. They then came out with a model that could be controlled by radio waves the next year.

As time went on, the ability and scope of pacemakers kept increasing. Their reliability also greatly improved. This was important because some common problems were that the pacemaker would go out of control and make the heart beat way too fast.

Other improvements came in the area of the pace or rhythm itself. One huge improvement was a pace maker that would change heartbeat based on the demand from the body if the patient was more or less active for example. Another advance was a pacemaker that would activate only when needed. It detects an irregular heartbeat and turns itself on.

This is a 1980’s Medtronic pacemaker.

This is a 1980’s Medtronic pacemaker.

In the 1990’s, pacemakers with microprocessors came out that could be programmed with a few algorithms which made them much ‘smarter’. They just ran much more smoothly, efficiently and reliably. The 2000’s saw improvements in the area of stimulating the heart in a fashion that was closer to the heart’s natural electrical system. They also became much smaller.

Now, many pacemakers run on a wi-fi based system where they can store data to an external hard drive and are much more responsive to the patient’s body. They can respond to even blood temperature and breath rate. Modern pacemakers can also act as a defibrillator if the heart stops. They really are incredible.

The future of pacemakers holds many promises. The batteries could still use improvement and better systems need to be made so that the body doesn’t reject the foreign device. It would also be nice if they could become smaller, maybe even as small as a dime as some project.

Here is a good summary video of how pacemakers work.

 

Before we go, here are some fun facts about pacemakers. The surgery is actually considered to be pretty minor. It takes a couple hours and patients typically stay just a night and don’t always get fully anesthetized.

Once you have a pacemaker, you always have to be conscious not to go anywhere that has a strong magnetic field because it could ruin the pacemaker. The batteries typically last about 6-7 years.

Pacemaker Usage

As pacemaker technology continued, they were mainly produced in the USA, UK and Europe and unfortunately they were too expensive to be used in many developing nations. Luckily, the technology started to pop-up in some second-world countries such as india. They started producing pacemakers in the early 1970’s for about a tenth of the cost of importing them.

Pacemaker improvement gave patients with heart problems a more sophisticated device that would give them more assurance of a longer and healthier life where they could return to their normal lifestyle.

Every year, approximately 200,000 pacemakers are implanted in the United States alone. That’s a lot of lives being changed for the better. As of 2009, Germany had the most implants per 1 million people. In total, over 600,000 are implanted every year.

Pacemakers Have Changed The Medical Field

I think it’s appropriate to end the story with a quote from the legendary Dr. William Mayo, founder of the world-renowned Mayo healthcare system also in Minnesota. He said, “These heroic men whose life work marked epochs in medicine we think of as individuals, but what they accomplished singly was perhaps of less importance than the inspiration they gave to the group of men that followed them.”

What started off as small experiments on animals and desperate patients turned into a global industry that allowed patients with bleak outlooks live more meaningful lives. Thousands of scientists across the world came together to change the medical device industry with innovation and dedication by inventing and improving the pacemaker.

 

References

https://www.youtube.com/watch?v=VIu-eSDAx4s

https://health.howstuffworks.com/human-body/systems/nervous-system/human-body-make-electricity1.htm

https://jamanetwork.com/journals/jama/article-abstract/260630

https://www.graduate.umaryland.edu/gsa/gazette/February-2016/How-the-human-body-uses-electricity/

http://www.futureofpersonalhealth.com/education-and-research/the-history-of-the-pacemaker-from-origins-to-modern-practice

https://www.medicinenet.com/pacemaker/article.htm#pacemaker_definition_and_facts

https://www.ncbi.nlm.nih.gov/pubmed/21707667

http://medind.nic.in/ibq/t05/i3/ibqt05i3p236.pdf