title: Diagnostic yield of device interrogation in the evaluation of syncope in an elderly population.
abstract: BACKGROUND
  Device interrogation has become a standard part of the syncope evaluation for patients admitted with permanent pacemakers (PPM) or implantable cardiac defibrillators (ICD), although few studies have shown interrogation yields clinically useful data. The purpose of this study is to determine the diagnostic yield of device interrogation as well as other commonly performed tests in the workup of unexplained syncope in patients with previously implanted PPMs or ICDs.
  
  
  METHODS
  We retrospectively reviewed records of 88 patients admitted to our medical center for syncope with previously implanted pacemakers between January 1, 2005 and January 1, 2015 using ICD-9 billing data.
  
  
  RESULTS
  Pacemaker interrogation demonstrated an arrhythmia as the cause for syncope in 4 patients (4%) and evidence of device failure secondary to perforation in 1 patient (1%). The cause of syncope was unknown in 34 patients (39%). Orthostatic hypotension was the most commonly identified cause of syncope (26%), followed by vasovagal syncope (13%), autonomic dysfunction (5%), ventricular arrhythmia (3%), atrial arrhythmia (2%), congestive heart failure (2%), stroke (2%), and other less common causes (8%). History was the most important determinant of syncope (36%), followed by orthostatic vital signs (14%), device interrogations (4%), head CT (2%), and transthoracic echocardiogram (1%).
  
  
  CONCLUSIONS
  Device interrogation is rarely useful for elucidating a cause of syncope without concerning physical exam, telemetry, or EKG findings. Interrogation may occasionally yield paroxysmal arrhythmias responsible for syncopal episode, but these rarely alter clinical outcomes. Interrogation appears to be more useful in patients with syncope after recent device placement.
authors.affiliation: Pat and Jim Calhoun Cardiology Center, University of Connecticut Health Center, 263 Farmington Ave., Farmington, CT 06032, United States; Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave, Boston, MA 02215, United States. Electronic address: rdangelo@bidmc.harvard.edu.
authors.forename: Robert N
authors.initials: RN
authors.lastname: D'Angelo
authors.affiliation: Pat and Jim Calhoun Cardiology Center, University of Connecticut Health Center, 263 Farmington Ave., Farmington, CT 06032, United States.
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Pickett
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology; D017147:Defibrillators, Implantable / Q000592:standards*; D004868:Equipment Failure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial / Q000592:standards*; D011159:Population Surveillance; D012189:Retrospective Studies; D013575:Syncope / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology*
keywords: Clinical electrophysiology; ICD interrogation; Pacemaker interrogation; Syncope