title: Is there a prognostic relevance of electrophysiological studies in bundle branch block patients?
abstract: BACKGROUND
  The present European guidelines suggest a diagnostic electrophysiological (EP) study to determine indication for cardiac pacing in patients with bundle branch block and unexplained syncope. We evaluated the prognostic relevance of an EP study for mortality and the development of permanent complete atrioventricular (AV) block in patients with symptomatic bifascicular block and first-degree AV block.
  
  
  OBJECTIVE
  The HV interval is a poor prognostic marker to predict the development of permanent AV block in patients with symptomatic bifascicular block (BFB) and AV block I°.
  
  
  METHODS
  Thirty consecutive patients (mean age, 74.8 ± 8.6 years; 25 males) with symptomatic BFB and first-degree AV block underwent an EP study before device implantation, according to current guidelines. For 53 ± 31 months, patients underwent yearly follow-up screening for syncope or higher-degree AV block.
  
  
  RESULTS
  Thirty patients presented with prolonged HV interval during the EP study (mean, 82.2 ± 20.1 ms; range, 57-142 ms), classified into 3 groups: group 1, <70 ms (mean, 62 ± 4 ms; range, 57-67 ms; n = 7), group 2, >70 to ≤100 ms (mean, 80 ± 8 ms; range, 70-97 ms; n = 18), and group 3, >100 ms (mean, 119 ± 14 ms; range, 107-142 ms; n = 5). According to the guidelines, patients in groups 2 and 3 received a pacemaker. The length of the HV interval was not associated with the later development of third-degree AV block or with increased mortality.
  
  
  CONCLUSIONS
  Our present study suggests that an indication for pacemaker implantation based solely on a diagnostic EP study with prolongation of the HV interval is not justified.
authors.affiliation: Department of Cardiology and Angiology, Lüdenscheid Clinic, Märkische Clinics GmbH, Lüdenscheid, Germany.|Department of Cardiology, Witten/Herdecke University, Germany.
authors.forename: Harilaos
authors.identifier: http://orcid.org/0000-0003-4206-630X
authors.initials: H
authors.lastname: Bogossian
authors.affiliation: Division of Electrophysiology, Department of Cardiovascular Medicine, University of Münster, Germany.
authors.forename: Gerrit
authors.initials: G
authors.lastname: Frommeyer
authors.affiliation: Department of Cardiology and Angiology, Lüdenscheid Clinic, Märkische Clinics GmbH, Lüdenscheid, Germany.
authors.forename: Kornelius
authors.initials: K
authors.lastname: Göbbert
authors.affiliation: Department of Cardiology and Angiology, Lüdenscheid Clinic, Märkische Clinics GmbH, Lüdenscheid, Germany.
authors.forename: Fuad
authors.initials: F
authors.lastname: Hasan
authors.affiliation: Department of Cardiology and Angiology, Lüdenscheid Clinic, Märkische Clinics GmbH, Lüdenscheid, Germany.
authors.forename: Quy Suu
authors.initials: QS
authors.lastname: Nguyen
authors.affiliation: Department of Cardiology and Angiology, Lüdenscheid Clinic, Märkische Clinics GmbH, Lüdenscheid, Germany.
authors.forename: Ilias
authors.initials: I
authors.lastname: Ninios
authors.affiliation: Department of Cardiology and Angiology, Lüdenscheid Clinic, Märkische Clinics GmbH, Lüdenscheid, Germany.
authors.forename: Dejan
authors.initials: D
authors.lastname: Mijic
authors.affiliation: Department of Cardiology and Angiology, Lüdenscheid Clinic, Märkische Clinics GmbH, Lüdenscheid, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Bandorski
authors.affiliation: Medical Clinic-Cardiology/Electrophysiology, Westmünsterland Clinic, St. Agnes-Hospital Bocholt I, Bocholt, Germany.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Hoeltgen
authors.affiliation: Department of Cardiology, HELIOS University Hospital Wuppertal, Germany.|Department of Cardiology, Witten/Herdecke University, Germany.
authors.forename: Melchior
authors.initials: M
authors.lastname: Seyfarth
authors.affiliation: Department of Cardiology and Angiology, Lüdenscheid Clinic, Märkische Clinics GmbH, Lüdenscheid, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Lemke
authors.affiliation: Division of Electrophysiology, Department of Cardiovascular Medicine, University of Münster, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Eckardt
authors.affiliation: Department of Cardiology and Angiology, Lüdenscheid Clinic, Märkische Clinics GmbH, Lüdenscheid, Germany.|Department of Cardiology, Witten/Herdecke University, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Zarse
mesh_terms: D000200:Action Potentials; D000368:Aged; D000369:Aged, 80 and over; D002036:Bundle of His / Q000503:physiopathology*; D002037:Bundle-Branch Block / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D002304:Cardiac Pacing, Artificial; D018572:Disease-Free Survival; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006339:Heart Rate; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012307:Risk Factors; D013997:Time Factors
keywords: 
  AV Block; 
  HV Interval; 
  PACEMAKER
  ; 
  SYNCOPE
  ; Bifascicular Block; Implantable Loop Recorder