Seeing i2i: The Inside Story of a Pacemaker Revolution

How a tech breakthrough led to the world's first dual chamber leadless pacemaker, the AVEIR DR system.

The story of our AVEIR DR system, the world's first dual chamber leadless pacemaker, starts with a team of engineers and a revolutionary idea.

Plus, a fish tank and two little "submarines." (Trust us: They factor in at a pivotal moment.)

Let's begin with the people — engineers who all specialize in designing pacemakers — and the groundbreaking idea they started working on almost a decade ago.

Simply put, they wanted to transform the traditional pacemaker as we know it. To replace its bulk and long wires with a duo of leadless devices that could be implanted in two separate chambers of the heart. And have this duo be able to communicate and work together as one functional system.

Was that even possible?

Well, as you probably guessed after reading the top of this story: Yes, it was. The AVEIR DR system is here, and it’s all thanks to a signature breakthrough. So, grab some swim goggles and dive in with us for a journey into the story of that breakthrough. We'll start by taking a quick dip into recent pacemaker history — and then jump into that fish tank we mentioned above.

Taking the Plunge

Until a few years ago, anyone in need of a pacemaker had to rely on technology that has been around, mostly unchanged, for 60 years. Doctors implant a pulse generator under the skin of your chest. From there, they run two long, insulated wires called "leads" down through the veins and into the upper- and lower-right chambers of the heart.

Our single-chamber AVEIR VR system, which received FDA approval in 2022, did away with the wires and jump-started our evolution to "leadless" pacemakers. Smaller than a triple-A battery, they can be implanted directly on the wall of the right ventricle in a minimally invasive procedure.

As the AVEIR VR system developed, the team always had the goal of expanding to both chambers, right atrium and right ventricle, said David Ligon, Director of Clinical Engineering, Leadless Applications at Abbott.

But they still needed to figure out a way for the two pacemakers in this theoretical system to "talk" to each other.

It took months and months of thinking to get over each new wave of challenges, said Matthew Fishler, Director of Systems Engineering, Chief Engineer for the Leadless Platform.

  • The two pacemakers needed to be able to communicate on every heartbeat, which happens, oh, about 40 million times a year, on average.
  • With such a massive amount of information to process and share, the team needed to engineer something sophisticated enough to handle the load.
  • They also needed to come up with a communication method that would not only work without wires but operate with as much battery-preserving energy efficiency as possible.

In the face of this monumental undertaking, they forged something brand-new: a concept they named "i2i" for "implant-to-implant" communication.

Which brings us back to the fish tank, and a key early test. For the dual chamber system to actually work, the team needed to determine if i2i could work in an environment that simulated the inside of the heart.

"We built little pacemaker cans — we called them 'submarines' — with the first test computer chip attached," Fishler recalled. "They were then submerged in a fish tank filled with salt water."

The submarines sent out their pings, and then came a rush of excitement: The experiment worked. The pacemakers transmitted back and forth through the saline solution.

Fishler: "The first time we actually saw this thing working was … "

"Eureka!" Ligon exclaimed.

"It was crazy. And a relief," Fishler said. "It was like, 'Wow, I think we actually have something here.' There was a lot more that needed to be done, but just establishing that this implant-to-implant communication could work was fundamental."

An Electric Discovery

The team's big breakthrough brought the AVEIR DR system to life, with technology that no other commercially available pacemaker contains.

But it's the potential human impact of this discovery that makes it so thrilling. So, let's take a closer look at i2i communication: How exactly does it work?

As Ligon and Fishler explained, the technology allows each pacemaker to send out a short sequence of low-voltage pulses. These pulses form a "packet" of digital information, a sort of status update that both pacemakers can interpret. For example: "I just paced." Or: "I'm sensing, and we need to step up the heart rate for a workout session."

Kind of like texting, right? Except that these exchanges move at a speed that would make even the most phone-addicted thumb wizard blush. Technically, they’re sent in less-than-a-heartbeat. We are talking milliseconds.

And how does all this activity not completely drain the pacemakers' batteries instantly? That’s another flash of brilliance within the design.

Our engineers built the i2i communication technology on an architecture that uses what's known as conducted communication. Stay with us, here: The basic idea is that, just like salt water can conduct electricity, the bloodstream can conduct the electrical pulses of information that our leadless pacemakers send out. (This is why our engineers tested it out in the salt water-filled tank.)

So, not only does i2i communication open up a channel between the two pacemakers, it also saves a whole lot of energy. The team basically invented a more efficient equivalent of Bluetooth for pacemakers.

"And, at the end of the day, AVEIR DR patients are getting the same therapy as with a traditional pacemaker," Ligon said. Therapy that helps keep the right atrium and right ventricle in synchrony and eliminates the risks associated with a traditional pacemaker's wire leads and surgical "pocket" incision.

Feel the Beat

To be clear: The fish tank represents just one set of experiments among many, and i2i is only one of many innovations that the AVEIR DR system brings to pacemaking.

To Ligon, the truly great thing about the system is how it makes patients' faces light up as they talk about having it without anyone being able to see it. To Fishler, it's seeing how his life's work has opened up new possibilities in cardiac rhythm management.

"This is really life-changing for some patients," Fishler said. "From that point of view, you're lucky if you get one of these products in your career to be part of. That's amazing."

Amazing what you can do with a big idea (and a small saltwater tank). We are in a new era of pacemaker technology, and that's no fish story.



Rx only

Brief Summary: Prior to using these devices, please review the Instructions for Use for a complete listing of indications, contraindications, warnings, precautions, potential adverse events and directions for use.

Indications: The Aveir™ Leadless Pacemaker system is indicated for management of one or more of the following permanent conditions: Syncope, Pre-syncope, Fatigue, Disorientation. Rate-modulated pacing is indicated for patients with chronotropic incompetence, and for those who would benefit from increased stimulation rates concurrent with physical activity. Dual-chamber pacing is indicated for patients exhibiting: Sick sinus syndrome, Chronic, symptomatic second- and third-degree AV block, Recurrent Adams-Stokes syndrome, Symptomatic bilateral bundle-branch block when tachyarrhythmia and other causes have been ruled out. Atrial pacing is indicated for patients with: Sinus node dysfunction and normal AV and intraventricular conduction systems. Ventricular pacing is indicated for patients with: Significant bradycardia and normal sinus rhythm with only rare episodes of AV block or sinus arrest, Chronic atrial fibrillation, Severe physical disability.

Intended Use: The Aveir™ Leadless Pacemaker (LP) is designed to provide bradycardia pacing as a pulse generator with built-in battery and electrodes for implantation in the right ventricle and/or right atrium. The LP is intended to provide sensing of intrinsic cardiac signals and delivery of cardiac pacing therapy within the implanted chamber for the target treatment group. The LP is also intended to operate optionally with another co-implanted LP to provide dual-chamber pacing therapy.

The Aveir™ Delivery Catheter is intended to be used in the peripheral vasculature and the cardiovascular system to deliver and manipulate an LP. Delivery and manipulation includes implanting an LP within the target chamber of the heart.

Contraindications: Use of the Aveir™ Leadless Pacemaker is contraindicated in these cases:

  • Use of any pacemaker is contraindicated in patients with a co-implanted ICD because high-voltage shocks could damage the pacemaker and the pacemaker could reduce shock effectiveness.
  • Single-chamber ventricular demand pacing is relatively contraindicated in patients who have demonstrated pacemaker syndrome, have retrograde VA conduction, or suffer a drop in arterial blood pressure with the onset of ventricular pacing.
  • Programming of rate-responsive pacing is contraindicated in patients with intolerance of high sensor driven rates.
  • Use is contraindicated in patients with an implanted vena cava filter or mechanical tricuspid valve because of interference between these devices and the delivery system during implantation.
  • Persons with known history of allergies to any of the components of this device may suffer an allergic reaction to this device. Prior to use on the patient, the patient should be counseled on the materials (listed in the Product Materials section of the IFU) contained in the device and a thorough history of allergies must be discussed.

Adverse Events: Potential complications associated with the use of the Aveir™ Leadless Pacemaker system are the same as with the use of single or dual chamber pacemakers with active fixation pacing leads including, but not limited to: Cardiac perforation, Cardiac tamponade, Pericardial effusion, Pericarditis, Valve damage and/or regurgitation, Heart failure, Pneumothorax/hemothorax, Cardiac arrhythmias, Diaphragmatic/phrenic nerve stimulation / extra-cardiac stimulation, Palpitations, Hypotension, Syncope, Cerebrovascular accident, Infection, Hypersensitivity reaction to device materials, contrast media, medications, or direct toxic effect of contrast media on kidney function, Pacemaker syndrome, Inability to interrogate or program the LP due to programmer or LP malfunction, Intermittent or complete loss of pacing and/or sensing due to dislodgement or mechanical malfunction of the LP (non-battery related), Loss of capture or sensing due to embolization or fibrotic tissue response at the electrode, Increased capture threshold, Inappropriate sensor response, Interruption of desired LP function due to electrical interference, either electromyogenic or electromagnetic, Battery malfunction/ premature battery depletion, Device-related complications (Premature deployment, Device dislodgement/embolization of foreign material, Helix distortion), Death. As with any percutaneous catheterization procedure, potential complications include, but are not limited to: Vascular access complications; such as perforation, dissection, puncture, groin pain, Bleeding or hematoma, Thrombus formation, Thromboembolism, Air embolism, Local and systemic infection, Peripheral nerve damage. General surgery risks and complications from comorbidities; such as hypotension, dyspnea, respiratory failure, syncope, pneumonia, hypertension, cardiac failure, reaction to sedation, renal failure, anemia, and death.