title: Syncope in patients paced for atrioventricular block.
abstract: OBJECTIVE
  Although syncope is the main reason for cardiac pacing in ∼40% of patients affected by atrioventricular block (AVB), very few data are available on the benefit of cardiac pacing in preventing syncopal recurrences.
  
  
  RESULTS
  We retrospectively evaluated 229 consecutive patients (124 males, age 80 ± 10 years) who had received a permanent pacemaker from January 2009 to December 2013 for AVB and syncope (94 patients, 41%) or AVB without syncope (135 patients, 59%). In patients with AVB and syncope, a third-degree or Mobitz II second-degree AVB had been documented in 73 and was only suspected in another 21, all of whom had bundle branch block. Follow-up was available in 223 patients. At 5 years, the actuarial syncope recurrence rate was 1% (95% CI, 0-3) in patients with documented AVB plus syncope and 3% (95% CI, 1-5) in those without syncope, whereas it was 14% (95% CI, 0-28) in patients with undocumented AVB plus syncope (P = 0.001). The actuarial combined recurrence rate of syncope and/or pre-syncope was 2% (95% CI, 0-4) in patients without syncope, 8% (95% CI, 0-17) in patients with documented AVB plus syncope, and 19% (95% CI, 1-37) in patients with undocumented AVB plus syncope, P = 0.002. All syncopes occurred in patients without overt structural heart disease (SHD), the corresponding actuarial estimate being 4% (95% CI, 0-6) at 1 year and 6% (95% CI, 4-8) at 5 years (P = 0.002 vs. patients with SHD).
  
  
  CONCLUSIONS
  Cardiac pacing is highly effective in preventing syncopal recurrences when AVB is documented. Syncope may recur in a non-negligible minority of paced patients when AVB is suspected but not documented and in patients without SHD.
authors: Arrhythmologic Centre, Department of Cardiology, Ospedali del Tigullio, Lavagna 16033, Italy.
authors: Milena
authors: M
authors: Aste
authors: Arrhythmologic Centre, Department of Cardiology, Ospedali del Tigullio, Lavagna 16033, Italy.
authors: Daniele
authors: D
authors: Oddone
authors: Arrhythmologic Centre, Department of Cardiology, Ospedali del Tigullio, Lavagna 16033, Italy.
authors: Paolo
authors: P
authors: Donateo
authors: Arrhythmologic Centre, Department of Cardiology, Ospedali del Tigullio, Lavagna 16033, Italy.
authors: Alberto
authors: A
authors: Solano
authors: Arrhythmologic Centre, Department of Cardiology, Ospedali del Tigullio, Lavagna 16033, Italy.
authors: Roberto
authors: R
authors: Maggi
authors: Arrhythmologic Centre, Department of Cardiology, Ospedali del Tigullio, Lavagna 16033, Italy.
authors: Francesco
authors: F
authors: Croci
authors: Arrhythmologic Centre, Department of Cardiology, Ospedali del Tigullio, Lavagna 16033, Italy.
authors: Diana
authors: D
authors: Solari
authors: Arrhythmologic Centre, Department of Cardiology, Ospedali del Tigullio, Lavagna 16033, Italy mbrignole@asl4.liguria.it.
authors: Michele
authors: M
authors: Brignole
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D054537:Atrioventricular Block / Q000628:therapy*; D002037:Bundle-Branch Block / Q000628:therapy*; D002304:Cardiac Pacing, Artificial; D005260:Female; D006801:Humans; D007558:Italy; D008297:Male; D010138:Pacemaker, Artificial; D012008:Recurrence; D012189:Retrospective Studies; D013575:Syncope / Q000453:epidemiology* / Q000517:prevention & control*
keywords: Atrioventricular block; Cardiac pacing; Syncope