REDUCED HEART-RATE-VARIABILITY AFTER RIGHT-SIDED STROKE

Background and Purpose Recently, asymmetries have been demonstrated in skin sudomotor and vasomotor function after unilateral cerebral lesio ns. The present study was performed to determine whether other bedside tests reflecting sympathetic and parasympathetic cardiovascular funct ions would reveal differences with respect to the side of cerebrovascu lar lesions. Methods Heart rate variability during deep breathing as w ell as blood pressure and heart rate changes during tilt and isometric handgrip was measured in a group of patients with a monofocal stroke and compared with similar data from age-matched patients with transien t ischemic attack and healthy control subjects. Results Compared with left-sided stroke and with the control subjects, stroke location on th e right side was associated with a reduced respiratory heart rate vari ability (P>.01); a reflex mainly under parasympathetic control. In con trast, reflexes mainly reflecting peripheral sympathetic function were equal for right- and left-sided lesions. Conclusions Since an imbalan ce in cardiac autonomic innervation may be crucial for the generation of cardiac arrhythmias and since reduced heart rate variability has be en associated with increased mortality, the findings suggest that the risk of sudden death may be correlated with lateralization and locatio n of the brain infarct after stroke.