Detecting AF Detecting AF Early with DX Technology

How DX-ICDs Provide AF Diagnostic Data

BIOTRONIK’s DX Technology addresses the shortcomings of traditional single-chamber ICDs by using a "floating atrial dipole" that senses electrical activity in the atria and provides timely device diagnostics, allowing physicians to detect atrial arrhythmias early.

Here’s a breakdown of how it works:

• Single-lead system with floating atrial dipole: DX uses a specialized ICD lead with two floating electrodes positioned in the atrium, capturing atrial electrical signals without a dedicated second lead.
• Four-fold amplification and filtering in the device: The ICD’s amplifier is finely tuned to detect and process the low-amplitude atrial signals, ensuring clear and reliable rhythm data from the atrium, even when AF reduces atrial wave amplitude.
• Accurate atrial diagnostics: This setup enables continuous monitoring of atrial arrhythmias, such as AF, providing diagnostic data directly from the atrium, comparable to dual-lead systems, but with fewer risks. It also stores atrial IEGM in the device diagnostics, just as it would with a dedicated atrial lead, making it easier for physicians to interpret the data and reach a diagnosis.

Unfortunately, it is difficult or even impossible to detect AF with a standard, single-chamber ICD. But with DX Technology, the single lead does the job of two: It treats dangerous arrhythmias in the ventricles while accurately monitoring the atria for AF and other arrhythmias. DX Technology significantly improves AF detection, reaching rates comparable to dual‑lead systems—about 13% compared to only 5% with standard single‑leads. Specifically, DDAF (formerly known as AHRE) detection rates are: DX: 13%, VR-ICD: 5.3%, and DR-ICD: 13%.[iii]

Better Diagnostics for Doctors, Safer for Patients

Doctors benefit from DX technology by gaining access to reliable atrial data from a single-lead ICD, enhanced by the dedicated atrial IEGM, which enables them to detect AF earlier, assess AF burden more accurately, and make faster, evidence-based treatment decisions. The system’s proven performance in clinical studies enhances diagnostic confidence while remote monitoring streamlines follow-up care.

DX systems are generally easier and faster for doctors to implant compared to dual-lead ICDs. Using only one lead instead of two reduces the complexity of accessing multiple heart chambers. This  lowers the risk of complications[iv], such as lead dislodgement or venous obstruction, thus improving the safety profile without losing diagnostic information, thanks to the two DX electrodes. Patients can feel more secure knowing their device is actively tracking silent AF episodes that may otherwise go unnoticed. 

Evidence-Based Advantages of DX Technology

DX Technology has been thoroughly evaluated and is supported by robust clinical evidence from over 30 clinical studies involving more than 6,500 patients[v]. The advantages of DX-ICDs were demonstrated in the SENSE trial, which compared 150 patients with DX-ICDs to matched cohorts with single- and dual-chamber devices. Results showed that DX matched dual-lead systems for detecting atrial high-rate episodes (13% detection rate), while standard single-lead ICDs lagged at 5.3%. Importantly, the DX system eliminated inappropriate shocks, compared with a 3.3% rate in single-lead ICDs, and reduced procedure complexity by avoiding the need for a second lead.

Additionally, in the largest clinical evaluation of DX Technology to date, the MATRIX study demonstrated that DX-equipped ICDs can accurately detect and reliably monitor subclinical AF in a real-world setting, due to their high sensing accuracy and consistent data transmission. It followed 2,054 patients with DX single‑lead ICDs for 24 months, across 119 centers in 24 countries and focused on device-detected atrial high-rate episodes and how well DX could monitor these over time using Home Monitoring.

The results:

• Outstanding accuracy: For DDAF (AHRE) episodes lasting one hour or more, DX achieved a 99.7% positive predictive value, meaning nearly all those alerts were true AF events
• Reliable remote monitoring: Among 1,841 patients using Home Monitoring, data transmission was active on 92.5% of days, enabling consistent, guideline-based remote oversight
• Silent AF isn’t rare: In patients without prior AF, 8.2% developed new-onset DDAF during follow‑up, and 31% of these progressed to longer durations
• High stroke risk needs early intervention: Of those with new DDAF, nearly 70% had episodes ≥1 hour, 80% had high stroke risk (CHA₂DS₂‑VASc), yet 69.5% were not on anticoagulants at the start, highlighting a critical gap that early detection could fill

When doctors detect new-onset DDAF episodes, which are often a sign of silent or subclinical AF, in patients who are at high risk of stroke but had no prior AF diagnosis, they typically respond by starting oral anticoagulant (OAC) therapy. In the REACT DX study, 69% of DX patients with no history of AF and new-onset DDAF detection began taking anticoagulants within an average of 24 days.[vi] This demonstrates that DDAF detection triggers clinical action: DX Technology provides an early warning, even in asymptomatic patients, enabling doctors to take timely, life-saving action to prevent potential blood clots and strokes. 

Information provided by DX Technology, using only a single lead, can help doctors detect and monitor AF burden to initiate timely, appropriate therapy for improved clinical outcomes, as well as detect and reliably monitor DDAF to provide the diagnostic information needed to inform intervention strategies. In short, data shows that DX Technology doesn’t just detect AF—it combines single-lead simplicity with atrial-level diagnostics, empowering physicians to detect AF early, act faster, and provide proactive guideline-based treatment. Backed by strong clinical data, it represents a smarter standard in ICD therapy.

This is the third blog post in our series for AF Awareness Month. Read about how our Closed Loop Stimulation (CLS) sensor can help physicians prevent AF. You can learn more about BIOTRONIK’s unique solutions for AF management here.

[i] Reinhold T, Belke R, Hauser T, et al. Cost Saving Potential of an Early Detection of Atrial Fibrillation in Patients after ICD Implantation. BioMed Research International, Volume 2018, 14 August 2018, Article ID 3417643.

[ii] Data on file from June 2025

[iii] Thomas G, et al. Subclinical atrial fibrillation detection with a floating atrial sensing dipole in single lead implantable cardioverter-defibrillator systems: Results of the SENSE trial. Journal of Cardiovascular Electrophysiology, Volume 30, Issue 10, October 2019, Pages 1994–2001.

[iv] Di Biase, HRS 2023 (CERTITUDE analysis)

[v] Data on file from June 2025

[vi] O’Connor M, et al. “REACT DX Registry: Real world reaction to atrial high-rate episodes detected in implantable cardioverter-defibrillator recipients with a DX lead” Technology And Health Care 2023;31:735-746