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 lesions. The present study was performed to determine whether other bedside tests reflecting sympathetic and parasympathetic cardiovascular functions would reveal differences with respect to the side of cerebrovascular lesions. Methods Heart rate variability during deep breathing as well 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 transient ischemic attack and healthy control subjects. Results Compared with left-sided stroke and with the control subjects, stroke location on the right side was associated with a reduced respiratory heart rate variability (P>.01); a reflex mainly under parasympathetic control. In contrast, reflexes mainly reflecting peripheral sympathetic function were equal for right- and left-sided lesions. Conclusions Since an imbalance in cardiac autonomic innervation may be crucial for the generation of cardiac arrhythmias and since reduced heart rate variability has been associated with increased mortality, the findings suggest that the risk of sudden death may be correlated with lateralization and location of the brain infarct after stroke.