title: External prolonged electrocardiogram monitoring in unexplained syncope and palpitations: results of the SYNARR-Flash study.
abstract: OBJECTIVE
  SYNARR-Flash study (Monitoring of SYNcopes and/or sustained palpitations of suspected ARRhythmic origin) is an international, multicentre, observational, prospective trial designed to evaluate the role of external 4-week electrocardiogram (ECG) monitoring in clinical work-up of unexplained syncope and/or sustained palpitations of suspected arrhythmic origin.
  
  
  RESULTS
  Consecutive patients were enrolled within 1 month after unexplained syncope or palpitations (index event) after being discharged from emergency room or hospitalization without a conclusive diagnosis. A 4-week ECG monitoring was obtained by external high-capacity loop recorder (SpiderFlash-T(®), Sorin) storing patient-activated and auto-triggered tracings. Diagnostic monitorings included (i) conclusive events with reoccurrence of syncope or palpitation with concomitant ECG recording (with/without arrhythmias) and (ii) events with asymptomatic predefined significant arrhythmias (sustained supraventricular or ventricular tachycardia, advanced atrio-ventricular block, sinus bradycardia <30 b.p.m., pauses >6 s). SYNARR-Flash study enrolled 395 patients (57.7% females, 56.9 ± 18.7 years, 28.1% with syncope, and 71.9% with palpitations) from 10 European centres. For syncope, the 4-week diagnostic yield was 24.5%, and predictors of diagnostic events were early start of recording (0-15 vs. >15 days after index event) (OR 6.2, 95% CI 1.3-29.6, P = 0.021) and previous history of supraventricular arrhythmias (OR 3.6, 95% CI 1.4-9.7, P = 0.018). For palpitations, the 4-week diagnostic yield was 71.6% and predictors of diagnostic events were history of recurrent palpitations (P < 0.001) and early start of recording (P = 0.001).
  
  
  CONCLUSIONS
  The 4-week external ECG monitoring can be considered as first-line tool in the diagnostic work-up of syncope and palpitation. Early recorder use, history of supraventricular arrhythmia, and frequent previous events increased the likelihood of diagnostic events during the 4-week external ECG monitoring.
authors.affiliation: Department of Cardiovascular-Cardiology 3, Electrophysiology, Ospedale Niguarda Ca' Granda, Piazza Ospedale Maggiore, 3, Milano 20162, Italy emanuelateresa.locati@ospedaleniguarda.it.
authors.forename: E T
authors.initials: ET
authors.lastname: Locati
authors.affiliation: Univeristy Hospital Vall d'Hebron, Barcelona, Spain University Hospital QuironDexeus, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Moya
authors.affiliation: Hospital Santa Marta, Lisbon, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: Oliveira
authors.affiliation: Inselspital, Bern, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Tanner
authors.affiliation: Uz Hospital, Leuven, Belgium.
authors.forename: R
authors.initials: R
authors.lastname: Willems
authors.affiliation: Department of Cardiovascular-Cardiology 3, Electrophysiology, Ospedale Niguarda Ca' Granda, Piazza Ospedale Maggiore, 3, Milano 20162, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Lunati
authors.affiliation: Lavagna Hospital, Lavagna, Genova, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Brignole
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000175:diagnosis*; D015716:Electrocardiography, Ambulatory; D005060:Europe; D005260:Female; D006801:Humans; D007391:International Cooperation; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D016019:Survival Analysis; D013575:Syncope / Q000175:diagnosis*
keywords: Ambulatory ECG monitoring; Arrhythmia diagnosis; External loop recorder; Palpitation; Syncope