Significance of syncope in patients with Alzheimer's disease treated with cholinesterase inhibitors

We describe three cases of patients with Alzheimer's disease who presented with cardiac syncope soon after initiation of a cholinesterase inhibitor therapy (donepezil). Bradyarrhythmia was documented in two patients, considered probable in one, and was presumed related to the cholinergic therapy. Pacemaker implantation seemed justified rather than donepezil cessation. Moreover, it permitted an increase in donepezil dosage.