Real-World Adverse Events Associated With the Sphere-9 Dual-Energy Arrhythmia Ablation Catheter

Sphere-9 is a lattice tip ablation catheter (Medtronic, USA) capable of delivering both pulsed field and radiofrequency ablation. It is approved for the treatment of atrial fibrillation. Adverse events related to this device have been reported to national databases. A systematic assessment of these reports is needed to understand the nature of device-related complications.

We queried the FDA Manufacturer and User Facility Device Experience (MAUDE) database between October 24, 2024 and October 24, 2025 to identify reports related to the Sphere-9 catheter. A total of 222 reports were included in the final analysis.

Of 222 reports, 148 (67%) resulted in clinical events. Of these, 107 were suspected to be related to the Sphere-9, including: VT/VF during/following energy delivery (n = 30), Stroke/TIA (n = 25), sinus node dysfunction/AV block (n = 23), pericardial effusion (n = 7), coronary spasm (n = 9), and phrenic nerve injury (n = 2). Catheter/defibrillator (ICD) related interactions were suspected in 10 of the VT/VF reports. There were 65 catheter related reports that did not appear to be associated with adverse clinical events, which included tissue/char formation on the catheter tip (n = 24), steam pop (n = 25), and mechanical entrapment (n = 7).

This early analysis of adverse events reported for the Sphere-9 catheter highlights complications including arrhythmias, such as VT/VF and AV block, and the risks associated with ICD-catheter related interactions.