Heart rate variability - a potential early marker of sub-acute post-stroke infections

• Published in: Acta neurologica Scandinavica Vol. 126; no. 3; pp. 189 - 196
• Main Authors: Günther, A., Salzmann, I., Nowack, S., Schwab, M., Surber, R., Hoyer, H., Witte, O. W., Hoyer, D.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-09-2012; Blackwell
• Subjects: Adult; Aged; Autonomic nervous system; Autonomic Nervous System - physiopathology; Biological and medical sciences; Blood Glucose; Blood Pressure; C-reactive protein; C-Reactive Protein - metabolism; Cerebrospinal fluid. Meninges. Spinal cord; EKG; Female; Heart rate; Heart Rate - physiology; heart rate variability; Humans; immunodepression; Infection; Infection - diagnosis; Infection - etiology; Ischemia; Leukocyte Count; Leukocytes; Male; Medical sciences; Middle Aged; Nervous system (semeiology, syndromes); Neurology; Predictive Value of Tests; Prospective Studies; Risk assessment; ROC Curve; Stroke; Stroke - complications; Stroke; Nervous system diseases; Acute; Cardiovascular disease; Cerebral disorder; Vascular disease; Infection; Heart rate; Autonomic nervous system; heart rate variability; Central nervous system disease; Early; Cerebrovascular disease; immunodepression
• ISSN: 0001-6314; 1600-0404
• DOI: 10.1111/j.1600-0404.2011.01626.x

Günther A, Salzmann I, Nowack S, Schwab M, Surber R, Hoyer H, Witte OW, Hoyer D. Heart rate variability – a potential early marker of sub‐acute post‐stroke infections. 
Acta Neurol Scand: 2012: 126: 189–196. 
© 2011 John Wiley & Sons A/S.
Objective –  Infection is the most relevant complication after acute ischemic stroke. Activity of the autonomic nervous system seems to control post‐stroke immunodepression. We investigated heart rate variability (HRV) indices that reflect autonomic readjustments as predictors of post‐stroke infection.
Materials and methods –  Forty‐three patients with acute ischemic stroke were enrolled in a prospective study. The predictability of sub‐acute infections (day 4 ± 1 after admission) was investigated in 34 patients without acute infection by means of HRV indices obtained in the acute period (48 h after admission).
Results –  Sub‐acute infection could be predicted in patients without clinical or paraclinical (white blood cell count and C‐reactive protein) signs of infection in the acute period at (i) day: increased HFnorm, reduced LFnorm and LF/HF; (ii) night: reduced LF and VLF (P < 0.05).
Conclusions –  HRV indices are candidates for early markers of developing post‐stroke infections, preceding routine blood samples. Thus, HRV‐based early diagnosis of post‐stroke infection should be investigated in more detail as it may have implications as a novel tool for timely and appropriate treatment. A corresponding continuous HRV‐based risk assessment using the ECG provided by the routine stroke monitoring system would be possible without any additional burden for patients and staff.