The company shared results from two real-world, retrospective analyses in post-ablation and pregnancy patient populations. It presented findings at Heart Rhythm Society (HRS) 2026 in Chicago.
Across both studies, the San Francisco-based company said its technology detected arrhythmias beyond 48 hours and within 14 days in a large proportion of patients (30% recurrent AFib and 60% arrhythmias in pregnancy. It said findings bear important implications for clinical assessment and decision-making.
iRhythm’s Zio long-term continuous monitoring (LTCM) features a prescription-only, patch-based ECG monitor that captures up to 14 days of continuous, uninterrupted data. It also utilizes the ZEUS (Zio ECG Utilization Software) system with an FDA-cleared AI algorithm. The system delivers an end-of-wear report reviewed and validated by qualified cardiac technicians.
The company said its HRS findings reinforce the value of continuous, uninterrupted monitoring up to 14 days with Zio ambulatory ECG devices. Outcomes reflect the growing clinical importance of detecting AFib alongside the increasing use of catheter ablation. Additionally, the company said they highlight the importance of arrhythmia detection in pregnancy.
“These data reinforce that monitoring approach and duration directly impact what is detected—and what is missed,” said Dr. Mintu Turakhia, chief medical and scientific officer and EVP, Advanced Technologies at iRhythm. Monitoring of 48 hours or less leads to false negatives of AF recurrence in 30% of those monitored in the year following-PVI. As AF burden and recurrence increase the risk of stroke and are directly actionable for clinical decisions regarding anticoagulation, antiarrhythmic, repeat ablation, and risk of heart failure — the data are clear that 14 days should be the minimum threshold for post-ablation monitoring.”
More about the data shared by iRhythm
Post-ablation AFib monitoring
iRhythm shared outcomes from a nationwide retrospective analysis of 11,051 patients monitored with Zio in the year following AFib ablation.
The company reported an overall AFib recurrence rate of 21% and a substantial portion of AFib recurrence detected beyond 48 hours and within 14 days. Investigators say AFib recurrence would often be missed with 24-48-hour monitoring, but 14-day monitoring delivered significant detection capabilities.
Data suggest that up to one in four patients with true AFib recurrence could experience misclassification as a false negative with short-term Holter monitoring compared to 14 days with Zio ambulatory ECG.
iRhythm said its findings provide new real-world evidence in a patient population that. has previously not been well quantified.
Pregnancy outcomes
A retrospective analysis of pregnant patients undergoing extended Zio monitoring identified arrhythmias in one in seven patients. It first detected arrhythmias after 48 hours in 60% of cases. Commonly used short-term Holter monitoring would miss these events, the company said.
Investigators detected arrhythmias in 37.7% of pregnant patients. The majority received evaluation for symptoms such as palpitations (62.8%). The company said this shows that rhythm abnormalities can occur even in patients without structural or other forms of heart disease.
iRhythm said it recorded 99.2% analyzable time, meaning nearly all recorded monitoring time produced usable heart rhythm data.
The company said its data provide new real-world evidence in a population where physiologic changes are associated with increased susceptibility to arrhythmias.
