title: Incidence and timing of potentially high-risk arrhythmias detected through long term continuous ambulatory electrocardiographic monitoring.
abstract: BACKGROUND
  Ambulatory electrocardiographic (ECG) monitoring is the standard to screen for high-risk arrhythmias. We evaluated the clinical utility of a novel, leadless electrode, single-patient-use ECG monitor that stores up to 14 days of a continuous recording to measure the burden and timing of potentially high-risk arrhythmias.
  
  
  METHODS
  We examined data from 122,815 long term continuous ambulatory monitors (iRhythm ZIO® Service, San Francisco) prescribed from 2011 to 2013 and categorized potentially high-risk arrhythmias into two types: (1) ventricular arrhythmias including non-sustained and sustained ventricular tachycardia and (2) bradyarrhythmias including sinus pauses >3 s, atrial fibrillation pauses >5 s, and high-grade heart block (Mobitz Type II or third-degree heart block).
  
  
  RESULTS
  Of 122,815 ZIO® recordings, median wear time was 9.9 (IQR 6.8-13.8) days and median analyzable time was 9.1 (IQR 6.4-13.1) days. There were 22,443 (18.3%) with at least one episode of non-sustained ventricular tachycardia (NSVT), 238 (0.2%) with sustained VT, 1766 (1.4%) with a sinus pause >3 s (SP), 520 (0.4%) with a pause during atrial fibrillation >5 s (AFP), and 1486 (1.2%) with high-grade heart block (HGHB). Median time to first arrhythmia was 74 h (IQR 26-149 h) for NSVT, 22 h (IQR 5-73 h) for sustained VT, 22 h (IQR 7-64 h) for SP, 31 h (IQR 11-82 h) for AFP, and 40 h (SD 10-118 h) for HGHB.
  
  
  CONCLUSIONS
  A significant percentage of potentially high-risk arrhythmias are not identified within 48-h of ambulatory ECG monitoring. Longer-term continuous ambulatory ECG monitoring provides incremental detection of these potentially clinically relevant arrhythmic events.
authors.affiliation: Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA. matthew.d.solomon@kp.org.|Stanford University School of Medicine, Stanford, CA, USA. matthew.d.solomon@kp.org.|Department of Cardiology, Kaiser Permanente Oakland Medical Center, 3600 Broadway, Oakland, CA, 94611, USA. matthew.d.solomon@kp.org.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Solomon
authors.affiliation: Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA.
authors.forename: Jingrong
authors.initials: J
authors.lastname: Yang
authors.affiliation: Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA.
authors.forename: Sue Hee
authors.initials: SH
authors.lastname: Sung
authors.affiliation: iRhythm Technologies, Inc, San Francisco, CA, USA.
authors.forename: Martha L
authors.initials: ML
authors.lastname: Livingston
authors.affiliation: iRhythm Technologies, Inc, San Francisco, CA, USA.
authors.forename: George
authors.initials: G
authors.lastname: Sarlas
authors.affiliation: iRhythm Technologies, Inc, San Francisco, CA, USA.
authors.forename: Judith C
authors.initials: JC
authors.lastname: Lenane
authors.affiliation: Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA.|Stanford University School of Medicine, Stanford, CA, USA.|Departments of Epidemiology, Biostatistics and Medicine, University of California, San Francisco, CA, USA.
authors.forename: Alan S
authors.initials: AS
authors.lastname: Go
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000453:epidemiology; D054537:Atrioventricular Block / Q000175:diagnosis / Q000453:epidemiology*; D001919:Bradycardia / Q000175:diagnosis / Q000453:epidemiology*; D015331:Cohort Studies; D015716:Electrocardiography, Ambulatory; D005260:Female; D006327:Heart Block / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D054138:Sinus Arrest, Cardiac / Q000175:diagnosis / Q000453:epidemiology*; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000453:epidemiology*; D013997:Time Factors