The insular cortex and the pathophysiology of stroke-induced cardiac changes.

Over the past fifty years considerable clinical evidence has accrued to demonstrate involvement of the cerebral cortex in cardiac function. Hemispheric stroke is often associated with electrocardiographic (ECG) evidence of cardiac repolarisation abnormalities. In addition strokes of all types are associated with specific pathological changes in the ventricular myocardium (myocytolysis). These effects are not attributable to concomitant cardiac ischemic disease in the majority of cases. The insular cortex has recently been shown to contain a site of cardiac representation. Prolonged stimulation of this region in the rat produces ECG and cardiac pathological changes similar to those observed after human stroke. It is suggested that middle cerebral artery stroke in certain cases either directly or indirectly leads to insular disinhibition, and increased autonomic activity represented by cardiac changes which significantly influence prognosis.