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Cardiac baroreceptor sensitivity is impaired after acute stroke
T G Robinson1, M James, J Youde
1University Division of Medicine for the Elderly, Glenfield Hospital, Leicester Royal Infirmary, UK.
Stroke
|September 26, 1997
Summary
Impaired cardiac baroreceptor sensitivity (BRS) is observed after acute stroke, potentially explaining blood pressure variability. Right hemisphere strokes show altered sympathovagal balance, possibly increasing cardiac arrhythmia risk.
Area of Science:
- Cardiovascular Physiology
- Neurology
- Biomedical Engineering
Background:
- Acute stroke is associated with blood pressure (BP) fluctuations and variability.
- The mechanisms behind these BP changes, potentially involving baroreceptor reflex arc and sympathetic nervous system activity, remain unclear.
- Previous studies on cardiac baroreceptor sensitivity (BRS) post-stroke primarily used invasive methods on chronic patients.
Purpose of the Study:
- To assess cardiac BRS and sympathovagal balance in acute stroke patients using novel noninvasive techniques.
- To investigate the relationship between acute stroke and impaired BRS.
- To explore potential differences in sympathovagal balance based on stroke laterality.
Main Methods:
- Simultaneous electrocardiography and noninvasive beat-to-beat BP monitoring in 37 acute stroke patients.
- Cardiac BRS assessment via power spectral analysis of pulse interval variability.
- Comparison of stroke patients with an age-, sex-, and BP-matched control group.
Main Results:
- Stroke patients exhibited significantly lower cardiac BRS compared to controls (P = .007 for combined alpha-index).
- Systolic BP variability showed increased high-frequency power in stroke patients (P < .001).
- Right hemisphere strokes were associated with reduced high-frequency pulse interval power, suggesting increased sympathetic tone (P = .03).
Conclusions:
- Impaired cardiac BRS may contribute to increased BP variability following acute stroke.
- No significant difference in overall sympathovagal activity measures between acute stroke patients and controls was found.
- Right hemisphere strokes demonstrated altered sympathovagal balance, potentially linked to cardiac arrhythmias, warranting further prognostic investigation.