title: Less syncope and milder symptoms in patients treated with pacing for induced cardioinhibitory carotid sinus syndrome: a randomized study.
abstract: OBJECTIVE
  The aim of this study was to examine the effect on symptoms in patients with induced cardioinhibitory carotid sinus syndrome (ICSS) when treated or not treated with a pacemaker.
  
  
  RESULTS
  Sixty patients with a history of syncope or pre-syncope and ICSS were randomized to receive a permanent pacemaker (P group, n = 30) or no pacing (NP group, n = 30). ICSS was defined as a ventricular pause (i.e. asystole) lasting 3 s or more in response to carotid sinus stimulation. The patients were seen at 3 and 12 months and at symptoms. At 12 months, the rate of syncope in the NP group was 40% (n = 12) compared with 10% (n = 3) in the P group (P = 0.008). The majority (11 of 12) of the syncope recurrences in the NP group occurred during the first 3 months. Pre-syncope occurred in two patients (7%) in the NP group and in eight (27%) in the P group. Ten patients (33%) with recurrent syncope in the NP group later crossed-over to receive pacemaker implant.
  
  
  CONCLUSIONS
  A history of syncope or pre-syncope, plus ICSS, was a strong predictor of subsequent syncope or pre-syncope. Most of the new symptoms occurred within 3 months. Pacemaker treatment effectively reduced syncope and/or resulted in milder symptoms.
authors.affiliation: School of Life Sciences, University of Skövde, PO Box 408, S-541 28 Skövde, Sweden. jan-eric.claesson@his.se
authors.forename: Jan-Eric
authors.initials: JE
authors.lastname: Claesson
authors.forename: Bo-Erik
authors.initials: BE
authors.lastname: Kristensson
authors.forename: Nils
authors.initials: N
authors.lastname: Edvardsson
authors.forename: Peter
authors.initials: P
authors.lastname: Währborg
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial; D002317:Cardiovascular Agents / Q000494:pharmacology; D002346:Carotid Sinus / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D012008:Recurrence; D012044:Regression Analysis; D013575:Syncope / Q000175:diagnosis* / Q000628:therapy*; D013577:Syndrome; D018667:Tilt-Table Test; D016896:Treatment Outcome