Hachinski and Sörös discovered that the control of the heart by the brain is asymmetric, with the fight/flight (sympathetic) response controlled by the right hemisphere and the rest and digest (parasympathetic) response controlled by the left hemisphere. Damage to one key component (the insula) can lead to heart irregularities and sudden death (Wikipedia).

"Summary: Sudden death is an important but widely under-recognised consequence of stroke. Acute stroke can disturb central autonomic control, resulting in myocardial injury, electrocardiographic abnormalities, cardiac arrhythmias, and ultimately sudden death. Experimental and clinical evidence suggests that autonomic imbalance is more frequent after infarcts involving the insular cortex, a crucial region for the control of sympathetic and parasympathetic autonomic functions. Cardiovascular comorbidities increase the risk of cardiac morbidity and mortality after stroke. Thus, many sudden deaths and serious non-fatal cardiac events after stroke are probably due to an interaction between cardiovascular and neurological causes. The exact mechanisms leading to sudden death remain incompletely understood. Further research is needed to investigate the autonomic consequences of acute stroke and to identify patients at high risk of sudden death" (Lancet Neurology).

Order of authorship in the original publication: Sörös, Hachinski.