AimsAlthough 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.Methods and resultsPatients 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), bradycardiatachycardia (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.ConclusionIn 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. © 2010 The Author.
- Bundle branch block