Heart Rate Variability Dynamics as Predictors of Functional Recovery and Mortality After Acute Ischemic Stroke

Area of Science:

• Neurology
• Cardiology
• Medical Statistics

Background:

• Autonomic dysfunction is common after acute ischemic stroke (AIS), impacting recovery and survival.
• Heart rate variability (HRV) measures autonomic balance but its prognostic role in AIS needs further evaluation.

Purpose of the Study:

• To prospectively evaluate the temporal changes in HRV after AIS.
• To determine the prognostic significance of HRV parameters for functional outcomes and mortality in AIS patients.

Main Methods:

• 148 AIS patients underwent HRV assessment (SDNN, LF, HF, LF/HF ratio) at baseline, 1 month, and 3 months.
• Functional outcome assessed using modified Rankin Scale (mRS); mortality recorded at 1 and 3 months.
• Multivariable logistic regression identified predictors of poor outcome (mRS > 2) and mortality.

Main Results:

• Over 3 months, HRV showed a shift towards parasympathetic predominance (increased SDNN, HF; decreased LF, LF/HF ratio).
• Higher SDNN strongly predicted better functional status and favorable outcomes (p < 0.001).
• Higher LF/HF ratio predicted poor outcomes at baseline and 3 months (p < 0.01, p < 0.001). 12.2% mortality at 3 months, predicted by comorbidities and altered HRV.

Conclusions:

• Post-stroke recovery involves progressive restoration of autonomic balance, indicated by HRV changes.
• Higher SDNN and lower LF/HF ratio are associated with improved functional recovery and survival after AIS.
• HRV analysis provides valuable prognostic insight for risk stratification in AIS patients.