"My name is Atul Verma. I'm a cardiac electrophysiologist in Montreal, Canada at the McGill University Health Centre, and today I'm going to be talking about the Volt AF IDE study results.

Tell us about balloon in basket PFA – what is the idea behind the design?

A lot of people have asked what the balloon in basket design is and what the motivations were behind designing it this way. I see this as a next-generation PFA tool — and what do I mean by that? We have seen some issues arising with first-generation PFA tools: hemolysis, reconnections occurring in the veins, and problems with coronary spasm when performing ablation in certain areas. So while PFA has been a great gift to us all, it has also come with its share of limitations. For any device moving forward, we have to overcome those limitations.
So how does the balloon and basket design do that? First, it gives you real-time contact assessment. Each of the eight splines provides a readout — not just binary contact or no contact, but the relative amount of contact you have with the tissue, which is critical for achieving durable lesions. Second, you can turn individual splines on or off. If one spline is not in good contact, you can turn it off and direct energy to the others. Another key factor is that the balloon inside the splines pushes energy towards the tissue — again helping with durability — while simultaneously insulating the bloodstream from stray PFA energy, resulting in very low levels of hemolysis.
Combined with ease of use, I think all of those factors make this a compelling tool. Various balloon devices have been used successfully in electrophysiology for years, and personally I found this balloon very easy to manipulate. It's simple to reach any of the veins. It's an over-the-wire system, but if you don't want to use it that way, you don't have to. Very flexible.

What did we learn from the VOLT AF IDE trial readout?

Here at AF Symposium 2026, we had the opportunity to present the VOLT AF IDE study 12-month results — and in my mind, the results have been incredible.
Starting with efficacy: our primary efficacy outcome included a composite of cardioversions, redo ablations, escalation or new antiarrhythmic drugs, and AF recurrence. Recurrence was monitored rigorously with TTM ECGs and Holters, with excellent compliance throughout the study. We all have that psychological threshold of getting past an 80% success rate for paroxysmal atrial fibrillation — and that's exactly what VOLT AF delivered. In paroxysmal patients with a PVI-alone approach, there was an 81% or higher success rate on the primary efficacy outcome. Translating that to simple AF recurrence — the metric used by other trials — we were nearly 85% free of any AF recurrence in paroxysmal patients. This is clearly surpassing that 80% threshold.
The study also examined persistent AF patients — approximately 150 of them, again with a PVI-alone approach. Here we achieved almost 65% freedom from recurrence, a very impressive number for PVI alone. Notably, 60% of these patients had heart failure with preserved ejection fraction, so these were not straightforward persistent AF cases.
On the safety side, the results were equally impressive. The overall serious adverse event rate was 1.9%. There was no evidence of coronary spasm, esophageal problems, pulmonary vein stenosis, or permanent phrenic nerve injury — none of the complications we have historically worried about in AF ablation trials.

How much time are we saving by mapping and ablating with the same tool?

One of the key advantages of the VOLT system is its integration with the Abbott NSIGHT mapping system. You can not only ablate with this tool — you can map with it at the same time, removing the need to introduce a separate mapping catheter. You simply go to the vein, collect a quick anatomy with the eight-spline device, and deliver two lesions per vein — around eight lesions in total for a full PVI. It's extremely time efficient.
In modern clinical experience following the trial — primarily in Europe where the device is approved — many operators are finding these procedures are completed in half an hour or less.
The take-home message is that this is a next-generation device specifically designed to address the limitations of first-generation PFA tools: hemolysis, inadequate contact, and energy not reaching the tissue. The results speak for themselves — well over 80% success in paroxysmal patients, approximately 65% in persistent AF, and an outstanding safety profile. Whether you want to perform PVI today or add posterior wall ablation in the future, I don't see why you wouldn't use this.