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Changes of circadian blood pressure patterns and cardiovascular parameters indicate lateralization of sympathetic
1Department of Neurology, Technical University of Munich, Germany.
Insights
Right-sided strokes significantly impact sympathetic nervous system activity, leading to reduced blood pressure variability and increased cardiac risks. This suggests a dominant role of the right hemisphere in sympathetic responses post-stroke.
Area of Science:
- Neurology
- Cardiology
- Autonomic Nervous System
Background:
- Investigating hemispheric asymmetry in stroke consequences on cardiovascular regulation.
- Examining sympathetic nervous system responses following left- versus right-sided brain infarction.
Observation:
- 35 patients with hemispheric brain infarction were analyzed for circadian blood pressure and cardiovascular variability.
- No significant differences in age, infarction size, or insular cortex damage were found between groups.
- Right-sided infarction correlated with reduced diastolic blood pressure variability and increased nocturnal blood pressure elevation.
Findings:
- Patients with right-sided infarction exhibited significantly lower circadian blood pressure variability and a higher incidence of nocturnal blood pressure increase.
- Elevated serum noradrenaline levels, QT prolongation, and cardiac arrhythmias were more frequent in patients with right-sided infarction.
- While insular infarction caused pronounced changes regardless of hemisphere, right-sided strokes involving the insula led to myocardial infarction in 13% of cases.
Implications:
- Findings suggest a lateralization of sympathetic activation, with right-sided brain infarction demonstrating a dominant sympathetic effect.
- This lateralization has potential implications for understanding stroke-related cardiovascular complications and developing targeted therapies.
- Further research is warranted to explore the mechanisms behind right-hemispheric dominance in sympathetic responses to stroke.
Abstract:
The effects of left- and right-sided hemispheric brain infarction on variability in circadian blood pressure and cardiovascular measures were investigated in 35 patients to test for asymmetry of the sympathetic consequences of stroke. No significant differences regarding age, size of infarction or extent and frequency of damage to the insular cortex could be detected between the two groups. Patients with right-sided infarction showed a significantly reduced circadian blood pressure variability [diastolic: -1% (95% CI -4 to 1) vs -6% (-9 to -2); P < 0.05] and a higher frequency of nocturnal blood pressure increase (47% vs 35%; P < 0.05) as compared with patients with left-sided infarction. Right-sided infarction was also associated with higher serum noradrenaline concentrations [546 pg/ml (95% CI 415-677) vs 405 pg/ml (266-544); P < 0.05], and ECG more frequently showed QT prolongation (53% vs 35%; P < 0.05) and cardiac arrhythmias (67% vs 20%; P < 0.005). However, irrespective of the hemisphere damaged, patients with insular infarction showed the most pronounced changes of these parameters. In addition, two patients with right-sided strokes (13%) involving the insula, but none with a left-sided infarction, developed myocardial infarction. These findings suggest lateralization of sympathetic activation with right-sided dominance for sympathetic effects following hemispheric stroke.