PocketECG® Blog. Remote Arrhythmia Monitoring Market

Cardiac Monitoring for AF: How Long is Long Enough?

Apr 30, 2018 9:10:00 AM / by Marek Dziubinski

New Data on the Relationship Between Monitoring Duration and Diagnostic Yield in Patients with Paroxysmal Atrial Fibrillation Will be Presented at HRS

What is the optimal duration of cardiac monitoring for detection of atrial fibrillation (AF)?  

What monitoring methods will result in higher diagnostic yields?

Will continuous monitoring for extended lengths of time improve detection of paroxysmal AF (PAF), which occurs intermittently and accounts for an estimated 25% - 60% of AF events?

Medicine doctor hand working with modern computer interface as medical concept

Studies have shown that the risk for stroke or thrombotic embolism increases about 5‐fold in patients with AF. In addition, a higher burden of AF events (i.e., total duration) is associated with higher stroke risk, and a total AF burden higher than 5.5 hours is predictive of future stroke. As the U.S. population of older adults continues to grow amidst an “alarming” increase in stroke risk factors, the need for better methods of AF detection is a matter of great urgency.

Is Your Monitoring Method Missing Too Many AF Events?

The intermittent occurrence of asymptomatic AF events presents difficulties in diagnosis and can lead to untreated risks for morbidity and mortality.  In a review of multiple clinical trials investigating the optimal duration of monitoring for PAF after acute ischemic stroke, the authors noted,

“Despite major advances in monitoring strategies, clinicians tend to miss the diagnoses of AF and especially paroxysmal AF due mainly to its asymptomatic presentation and the rather limited duration dedicated for monitoring for AF after a stroke … although patients in common practice receive a single 24- or 48-hour Holter monitor after a cryptogenic stroke as per the current guidelines for stroke management the diagnosis of PAF is very often missed.”

Although various factors affect the rate of detection, including how AF duration is defined, the time interval from the initial stroke to the start of monitoring and patient characteristics, the length of monitoring is always cited as a prime influence. In the previously cited study, the authors concluded that increasing the monitoring duration for AF after a cryptogenic stroke to at least 72 hours will indeed enhance the detection rates.

Other examples that support the contention that 24- to 48-hour monitoring may be missing too many AF episodes include:

  • A study evaluating the usefulness of continuous ECG monitoring (CEM) found that using CEM increases the detection yield of AF after a stroke by 5.29-fold compared to the routine 24-hour Holter ECG.
  • A Journal of the American Heart Association Special Report on Heart Rhythm Monitoring Strategies for Cryptogenic Stroke found that longer durations of cardiac monitoring led to increased yield and recommended at least 30 days of monitoring.
  • Another study using a continuous monitoring method found that a substantial proportion of patients with PAF had their first episodes more than 48 hours after the start of the monitoring period.

New Study Compares Online and Offline Diagnostic Monitoring Methods for PAF

New research on this important issue will be presented by MEDICALgorithmics S.A, one of the world’s largest companies specializing in cardiac monitoring, at the Heart Rhythm Society Annual Scientific Sessions in Boston in May. It will be the first large study to compare the PAF diagnostic capabilities of continuous online monitoring with Holter monitors and offline patches.

Based on more than 16,000 mobile telemetry reports generated by the PocketECG system, this study (Abstract #9300) provides a statistical analysis of the diagnostic yield of online, full-disclosure ECG monitoring in comparison with two offline fixed duration methods.  It also provides new insights into the potential benefits of allowing physicians to shorten or extend the monitoring duration depending on real-time diagnostic information.

PocketECG is one of the world’s leading mobile cardiac telemetry systems for the diagnosis and monitoring of arrhythmias.  It is the only solution that provides continuous streaming of the full disclosure ECG signal, symptom tracking capabilities and built-in physical activity monitoring for up to 30 days. PocketECG captures the onset and offset of every arrhythmia and classifies morphology for every beat to help you make a more timely and precise diagnosis.

To learn more about the HRS monitoring study and new developments in continuous arrhythmia monitoring technology, visit us at #HRS2018 in Boston, May 9 -12, Booth #1312, or visit




Topics: Market digest, HRS

Marek Dziubinski

Written by Marek Dziubinski

Ph.D. scientist, innovator