Functional neuroimaging of cardiac patients following coronary artery bypass graft surgery

Coronary artery bypass graft (CABG) surgery is a common surgical procedure carried out to relieve conditions of heart disease. Unfortunate and well-documented consequences of CABG are neurological sequelae and cognitive deficits. As part of a larger study of these post-surgical phenomena we compared post-CABG patients with matched healthy controls in a functional MRI investigation responses to visual stimuli. The visual stimuli (faces and words) were chosen to activate posterior parietal and temporal areas of cortex Œ areas identified as ‡watershedŸ areas of the cerebral vascular supply. It is these watershed areas, at the cerebral arterial boundaries, that are thought to be particularly vulnerable to the effects of embolic insult or hypoperfusion occasioned by the CABG surgery. The fMRI responses showed greatly reduced activation in the post-CABG patients. The results are discussed in terms of the clinical condition and possible neuroprotective measures for these patients