title: Diagnosis, management, and outcomes of patients with syncope and bundle branch block.
abstract: OBJECTIVE
  Although patients with syncope and bundle branch block (BBB) are at high risk of developing atrio-ventricular block, syncope may be due to other aetiologies. We performed a prospective, observational study of the clinical outcomes of patients with syncope and BBB following a systematic diagnostic approach.
  
  
  RESULTS
  Patients with ≥1 syncope in the last 6 months, with QRS duration ≥120 ms, were prospectively studied following a three-phase diagnostic strategy: Phase I, initial evaluation; Phase II, electrophysiological study (EPS); and Phase III, insertion of an implantable loop recorder (ILR). Overall, 323 patients (left ventricular ejection fraction 56 ± 12%) were studied. The aetiological diagnosis was established in 267 (82.7%) patients (102 at initial evaluation, 113 upon EPS, and 52 upon ILR) with the following aetiologies: bradyarrhythmia (202), carotid sinus syndrome (20), ventricular tachycardia (18), neurally mediated (9), orthostatic hypotension (4), drug-induced (3), secondary to cardiopulmonary disease (2), supraventricular tachycardia (1), bradycardia-tachycardia (1), and non-arrhythmic (7). A pacemaker was implanted in 220 (68.1%), an implantable cardioverter defibrillator in 19 (5.8%), and radiofrequency catheter ablation was performed in 3 patients. Twenty patients (6%) had died at an average follow-up of 19.2 ± 8.2 months.
  
  
  CONCLUSIONS
  In patients with syncope, BBB, and mean left ventricular ejection fraction of 56 ± 12%, a systematic diagnostic approach achieves a high rate of aetiological diagnosis and allows to select specific treatment.
authors: Hospital General Vall d'Hebrón, Universitat Autònoma de Barcelona, Barcelona, Passeig Vall d'Hebron 119-129, Barcelona, Spain. amoya@comb.cat
authors: Angel
authors: A
authors: Moya
authors: Roberto
authors: R
authors: García-Civera
authors: Francesco
authors: F
authors: Croci
authors: Carlo
authors: C
authors: Menozzi
authors: Josep
authors: J
authors: Brugada
authors: Fabrizio
authors: F
authors: Ammirati
authors: Attilio
authors: A
authors: Del Rosso
authors: Alejandro
authors: A
authors: Bellver-Navarro
authors: Jesús
authors: J
authors: Garcia-Sacristán
authors: Miriam
authors: M
authors: Bortnik
authors: Lluis
authors: L
authors: Mont
authors: Ricardo
authors: R
authors: Ruiz-Granell
authors: Xavier
authors: X
authors: Navarro
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002037:Bundle-Branch Block / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D011446:Prospective Studies; D012008:Recurrence; D013575:Syncope / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000209:etiology; D014694:Ventricular Outflow Obstruction / Q000209:etiology