iRhythm Technologies presented findings from two large retrospective analyses at the American College of Cardiology (ACC) 2025 Scientific Sessions in Chicago. Drawing from data from more than 1.1 million patients using the Zio long-term continuous monitoring (LTCM) devices, the studies reveal that short-term (24-48-hour) monitoring methods like Holter monitors often fail to detect actionable arrhythmias. Among patients reporting daily symptoms, nearly 64 percent of actionable arrhythmias remained undetected within the first 48 hours. The studies also show that symptom frequency alone is not a reliable indicator of arrhythmia burden and that the mean time to the first arrhythmic event exceeded 48 hours across all arrhythmia types. Additionally, symptom–rhythm correlation was found to be low, suggesting that relying solely on patient-reported symptoms could lead to missed diagnoses.
These results support the need for longer monitoring durations, as offered by Zio LTCM, which enables continuous tracking for up to 14 days. The research further aligns with findings from the CAMELOT study, highlighting Zio's higher diagnostic yield and reduced need for repeat testing. With up to 16 million Americans affected by arrhythmias and substantial healthcare costs tied to undiagnosed conditions, these new insights emphasize the clinical and economic advantages of extended monitoring to improve patient outcomes and reduce missed arrhythmias.
