Two Ventricular Fibrillation Cases Reported Post-WiSE Implant, One Fatal
EBR Systems has completed its internal probe into two serious complications, including one death, linked to its WiSE cardiac pacing system at a single site. The company deems the events isolated and related to a known risk mitigated by procedural adherence.
- Two patients suffered ventricular fibrillation post-implant
- One patient died; incidents confined to a single site
- Events linked to known ultrasound-induced stimulation risk
- FDA to review using EBR’s investigation and site data
- Commercial implants continue at other sites without interruption
Serious Complications Isolated to One Site
EBR Systems (ASX:EBR) has wrapped up its internal investigation into two serious adverse events following implantation of its WiSE wireless cardiac pacing system. Both patients at a single site developed ventricular fibrillation during next-day transthoracic echocardiograms (TTE), a complication that led to one patient’s death. The company emphasised these events are isolated, with no other occurrences reported across its commercial implant experience.
Known Risk Linked to Ultrasound Imaging
The incidents relate to a documented risk associated with the WiSE system’s passive acoustic operating principle. External ultrasound, such as that used during TTE imaging, can inadvertently stimulate the heart, causing untimed pacing or arrhythmias. This hazard is detailed in the FDA-approved WiSE system labelling and echo protocols, which prescribe continuous ECG monitoring, immediate probe removal upon unintended stimulation, and availability of an external defibrillator during imaging.
FDA Review and Limited Site Cooperation
The U.S. Food and Drug Administration will conduct its own review of the events, using data submitted by the implant site and EBR’s internal findings. However, EBR reported multiple unsuccessful attempts to obtain additional clinical records from the site, limiting the scope of its review. A summary of EBR’s analysis will be publicly posted on the FDA’s MAUDE database following FDA schedules.
Commercial Activity Continues Amid Investigation
Despite the gravity of the events, EBR stated it has no ongoing safety concerns at this stage and that commercial implants are proceeding as usual at other sites. The company’s internal data suggest the complication rate remains below the levels reported in the premarket approval application to the FDA, with no prior deaths linked to this specific risk.
Investor Engagement Planned
EBR’s senior management will host an investor webinar coinciding with the release of its preliminary Q2 2026 results to discuss these developments. This engagement offers a timely opportunity for investors to hear directly from the company amid ongoing commercial expansion, which recently included 46 implants and multiple new contracts in Q2 2026.
Bottom Line?
While EBR pins the serious complications on a known, manageable risk, the lack of site cooperation and a patient death mean regulatory scrutiny and investor caution will persist.
Questions in the middle?
- Will the FDA’s review prompt changes to WiSE system labelling or imaging protocols?
- How might limited site data impact EBR’s ability to manage and mitigate future risks?
- Could these events affect physician adoption rates or commercial rollout momentum?
