There is increasing recognition of the interaction between cardiovascular disease and cognitive function.¹ The effects of cardiovascular performance on cognitive function remain unclear, however. This is relevant for patients who require pacemaker implantation for symptomatic bradycardia, as many such patients are elderly and the use of suboptimal pacing modes may expose them to intermittent hypotension and increased risks of atrial fibrillation. Intermittent hypotension, associated with impaired cerebral autoregulation in the elderly, may cause cerebral ischaemia, and atrial fibrillation is the predominant cause of multi-infarct dementia as well as a recognised risk factor for Alzheimer’s dementia. Through these conditions pacing therapy may have an adverse effect on cerebral and cognitive function.

We therefore designed this study to assess the cognitive function of patients with symptomatic bradycardia after implantation of a permanent pacemaker and to test the hypothesis that single chamber ventricular (VVI(R)) pacing is detrimental to cognitive function when compared with atrial based pacing.

METHODS

Patients recruited to either of two multi-centre pacemaker trials (UKPACE or STOP-AF) at the Freeman Hospital in Newcastle upon Tyne, between January 1997 and May 1999, were invited to participate after randomisation to VVI(R) or atrial based pacing. Cognitive assessments were undertaken one month, one year, and two years after pacemaker implantation using CAMCOG (the cognitive section of the Cambridge examination for mental disorders of the elderly) and CANTAB (Cambridge neuropsychological test …