An estimated 1.43 million pacemakers were implanted worldwide in 2023 alone. These advanced cardiac devices have come a long way since the earliest inventions and understandings of heart rhythm and cardiac pacing.
Let us explore the incredible journey of the pacemaker and what the future holds for this life-saving technology.
Early Pacing Attempts and Breakthroughs
The pacemaker as we know it today began nearly 100 years ago with the first external cardiac pacemakers, developed on opposite sides of the Pacific Ocean.
In 1928, Australian anesthesiologist Mark Lidwell used intermittent electrical stimulation from a needle-based device conducting alternating currents to revive the heart of a baby born in cardiac arrest. Four years later, American physiologist Albert Hyman used a similar needle-based system to deliver an “intra-cardiac injection of stimulant drugs” (like epinephrine). However, it was not the drugs that stimulated the heart but an “action current” from the needle puncturing the cardiac wall.
Hyman dubbed his spring-wound, hand-crank motorized device an “artificial pacemaker.” Hyman’s goal for his “pacemaker” was to restore a normal heartbeat in patients whose heart had stopped accidentally or in stillborn infants, not unlike the modern defibrillator. It would take another 20 years and another country to develop a viable electronic cardiac pacemaker.
In researching how to enable open-heart surgery at the University of Toronto’s Banting Institute, cardiologists Wilfred Bigelow and John Callaghan experimented with hypothermia to immobilize the heart enough for surgery but were unable to stimulate and maintain regular heartbeat in the hypothermic state. At the same time, an electrical engineer named John Hopps was researching the use of radiofrequency reheating in pasteurization for the National Research Council Canada (NRC). The NRC brought the two groups of researchers together, and Hopps hypothesized that electrical pulses could stimulate the heart and that “repetitive stimuli” (or pacing) could allow this to be sustained during open-heart surgery and possibly longer.
Hopps and a team went to work experimenting and refining a viable system for “pacemaker-induced cardiac stimulation.” These experiments led Hopps to develop the first external pacemaker in 1950. While it did successfully sustain pacing and control heart rate, it was a bulky, external device with vacuum tubes that was primarily used in hospitals. Still, Hopps’ device was a significant breakthrough in using electrical stimulation to consistently regulate heartbeat, laying the foundation for future pacemaker advancements, this time in Europe.
On October 8, 1958, the first electronic pacemaker was successfully implanted in a patient by a team of Swedish doctors led by Åke Senning and engineer Rune Elmqvist. Taking the pacemaker from an external, table-top device that was attached to a patient via wires and tubes to a device that functioned within the patient’s body called for some ingenuity. This first implantable pacemaker was entirely hand-made and powered by nickel-cadmium batteries, with the mold to produce it based on a can of shoe polish. It was implanted in the abdominal wall of the recipient, Arne Larsson, but had to be charged by being “plugged in” to an “external mains-powered vacuum tube device via an external coil” once a week for 12 hours.
While primitive (and even scary!) by today’s medical technology standards, this successful device marked the beginning for implantable cardiac pacemakers and their life-lengthening potential. Larsson would go on to receive more than 22 units and numerous surgical interventions until his death in 2001—43 years after receiving the first implantable pacemaker.
Modern Pacemakers and Advancements
Since these early breakthroughs, pacemaker technology has advanced at a rapid pace, leading to modern, sophisticated devices that are smaller, last longer, and are more efficient in regulating heart rhythm.
Smaller Size
Today’s devices are compact, with some as small as a vitamin capsule. These modern pacemakers are implanted under the skin, usually near the collarbone, and connected to the heart via wires (called leads) through veins to electrodes inside the heart chamber, delivering the electrical impulses that regulate the heartbeat.
Multi-Chamber and Rate-Responsive Pacemakers
Today’s pacemakers are tailored to specific chambers of the heart, with the number of leads and contraction generation needed for a patient’s specific heart rhythm condition.
- Single-chamber pacemakers work on one chamber of the heart, with a single lead going to either the right atrium or the right ventricle.
- Dual-chamber pacemakers use two leads to connect to both the right atrium and the right ventricle, regulating both chambers of the heart. This helps the two chambers work together for more natural heart rhythms compared to single-chamber devices.
- Biventricular pacemakers synchronize the contractions of the left and right ventricles using three leads: one in the right atrium, one in the right ventricle, and one in the left ventricle. These pacemakers are most often used in patients suffering from heart failure.
- Rate-responsive pacemakers can adjust the pacing rate based on the patient’s activity level, ensuring that the heart rate increases during exercise and decreases during rest, mimicking the body’s natural response.
Longer Battery Life
Early pacemakers required frequent battery replacements and even charging that meant more invasive procedures for patients. Modern pacemakers use lithium batteries that can last an average of five to seven years, with the latest battery technology reaching a lifespan of 10 to 15 years. This can significantly reduce the number of replacement procedures and devices for patients.
Remote Monitoring
Modern pacemakers are equipped with remote monitoring capabilities. Patient heart and device performance data can be transmitted from the pacemaker to a healthcare provider via a home monitoring system. This remote monitoring functionality has seen expanded capabilities thanks to smart devices and wireless technology. For example, the Assurity MRI pacemaker manufactured by Abbott features wireless remote monitoring that provides doctors with both patient diagnostic data and device performance measurements so they can monitor and track patient heart rhythms and detect the warning signs of any device issues.
Looking Forward: A Future of Continued Innovation
The future of pacemaker technology promises even more exciting developments that can enhance patient comfort, device longevity and functionality.
Leadless Pacemakers
Leadless pacemakers are self-contained units that are implanted directly into the heart via a minimally invasive procedure. These devices eliminate the need for leads connecting the pacemaker to the heart. This reduces the risk of complications like infection and lead displacement, which can necessitate an additional procedure to reattach the lead. The small, single-unit size and placement in the heart also improves patient comfort.
Leadless pacemaker technology has primarily been used with single-chamber pacemakers until last year when Abbot received FDA approval for their new AVEIR dual chamber leadless pacemaker, the first of its kind in the world. The leadless system consists of two tiny pacemakers (smaller than a AAA battery) using Abbot’s proprietary i2i communication technology for synchronized “beat-to-beat communication” between the two pacemakers and the two chambers of the heart.
Artificial Intelligence
Artificial Intelligence (AI) has the potential to revolutionize pacemaker technology with its enhanced data analysis. AI algorithms can analyze huge volumes of data to identify trends and insights that humans might miss or simply don’t have the capacity to analyze. Training machine learning models on large patient datasets has the potential to improve the detection of abnormal heart rhythms and dangerous arrhythmias, so patients are diagnosed and treated faster. Similarly, AI analysis of performance data collected from numerous pacing devices can improve overall pacemaker technology.
AI can also personalize and optimize a single pacemaker for a single patient. By analyzing patient-specific data, AI can learn from the patient’s heart patterns and adjust the device settings in real-time in response to the patient’s heart rhythms. AI analysis of that device’s performance data can identify patterns or anomalies that could indicate an issue, allowing for proactive maintenance that ensures safe and optimal pacemaker performance for the patient.
Bioelectronics
The next generation of pacemakers have the potential to work more naturally with the body’s physiological processes. Researchers at the University of Washington have developed a pacemaker “sleeve” with energy-harvesting technology that uses the “oscillating cardiovascular pressure” from the beat of the heart to partially re-charge the battery of a leadless pacemaker, potentially extending device lifespan.
Researchers have also developed a wireless, biodegradable pacemaker, a temporary device designed to dissolve harmlessly in the body once it’s no longer needed. Current temporary pacemakers use wires to connect a patient to an external power and pacing device. This implantable, biodegradable device could reduce the risk of complications and discomfort for patients who need temporary pacing support due to a heart attack or heart surgery.
The Global Need for Pacemakers
As technology continues to advance, pacemakers will become even more effective, less invasive, and better integrated with the human body. However, these latest technologies and innovations are often slow to arrive in countries with limited resources and the greatest needs. As a result, an estimated 2 – 3 million people in developing countries die every year because they cannot afford pacemaker surgery.
ForHearts Worldwide is bridging this gap by providing life-saving cardiovascular devices, implantation procedures, and follow-up care and monitoring to people in need in 6 countries right now. For 40 years, we have been committed to doing all we can ForHearts in need. Now, we are excited to announce our new partnership with the Pacemaker Club, an online community where people living with cardiovascular devices can connect, share information, and support one other.
You can support hearts in need around the world with the gift of a life-saving pacemaker. See how you can be part of the ForHearts mission through our donation opportunities.