Abstract W MP63: Diagnostic Yield of an Extended Ambulatory Cardiac Rhythm Monitor in Patients With TIA or Stroke
Background: In the evaluation of patients with TIA or stroke, the detection of AF changes the recommended anti-thrombotic regimen from treatment with an antiplatelet agent to oral anticoagulation. Detection of supraventricular tachycardia (SVT) may also be relevant as it is associated with an increased risk of AF. This study describes the feasibility and diagnostic yield of the Zio® Patch, a leadless, single-use, small, lightweight, and water-resistant cardiac rhythm monitor that provides continuous cardiac monitoring for up to 14 days.
Methods: We obtained de-identified monitoring data from the manufacturer and servicer of the ZioPatch (iRhythm Technologies). Patients who were monitored between January 2012 and June 2013 and whose indication for monitoring, as entered by the ordering provider, was TIA or stroke were included. The duration of monitoring, the number and type of arrhythmias, and the time to first arrhythmia were documented. AF was defined as R-R irregularity for more than 30 seconds in duration.
Results: 1,171 monitoring reports were analyzed. The average patient age was 67.9 years. Fifty-five percent of patients were male. The mean monitor wear time was 10.9 days and the median wear time was 13.0 days (interquartile range 7.2-14.0). The median analyzable time relative to the total wear time was 98.7% (IQR 96.0-99.5%). AF was present in 4.8% of all reports (4.2% PAF and 0.6% chronic AF). The mean duration before the first episode of PAF was 1.5 days and the median duration was 0.4 days. 14.3% of first PAF episodes occurred after 48 hours. The mean PAF burden was 12.7% of the total monitoring duration. SVT of 8 beats or more was present in 51% of the records.
Conclusion: Virtually the entire duration of monitoring with the ZioPatch yields analyzable data that allows for the detection of cardiac arrhythmias. Among TIA and stroke patients, AF was present in approximately 5% of the records and SVT in 50%. The first episode of PAF frequently occurred more than 48 hours after the start of monitoring. This suggests that Holter (24-48 hour) monitoring is insufficient and supports extended cardiac monitoring in TIA and stroke patients. Further studies are needed to determine which stroke patients are at greatest risk for AF and to assess the clinical significance of SVT.
Author Disclosures: C.E. Tung: None. M.G. Lansberg: None. M.P. Turakhia: None.
- © 2014 by American Heart Association, Inc.