Relationship between ischemic stroke locations, etiology subtypes, neurological outcomes, and autonomic cardiac function.

Background Post-stroke autonomic nervous dysfunction measured with heart rate variability (HRV) is correlated with the traditional risk factors and poor outcome. This study aimed to investigate the association between HRV and infarct locations, etiology subtypes, and neurological functional outcomes in patients with acute ischemic stroke (AIS). Methods In this prospective observational study, 186 consecutive patients were assigned to four major stroke severity categories based on the National Institutes of Health Stroke Scale score (NIHSS) and the modified Rankin Scale score (mRS): mild (NIHSS 0-4) stroke, moderate (NIHSS 5-14) stroke, 'favorable' (mRS 0-2) group, and 'unfavorable' (mRS 3-5) group. HRV time domain parameters were applied to evaluate the autonomic function of patients within 1 week after admission. All patients were classified into different etiology subtypes based on the TOAST (modified Trial of ORG 10172 in Acute Stroke Treatment) classification. The association of HRV with stroke location, etiology subtypes, neurological outcome was explored for all participants. Univariate and multivariate analyses were applied to explore the prediction value of HRV. Results 160 participants had large artery atherosclerotic infarction (LAA), 61 had right internal carotid artery system infarction (R-ICA), and 61 had vertebrobasilar artery system infarction (VB). Root-mean-square of differences (RMSSD) of adjacent RR intervals and the proportion calculated by dividing the interbeat interval differences >50 ms (pNN50) in patients of VB group was significantly lower than those of patients in R-ICA group (P < 0.01). HRV parameters in the LAA group was significantly lower than non-LAA group (P < 0.01). At discharge, significant lower HRV presented in the unfavorable group and moderate group (P < 0.05). After logistic univariate and multivariate analysis, lower SDNN (OR = 1.019; 95% CI = 1.003-1.035;p= 0.021) was independently associated with unfavorable mRS and higher NIHSS at discharge (OR = 1.013; 95%CI = 1.003-1.024;p= 0.015). Only SDNN showed predictive value for mRS >= 3 (OR = 1.012; 95%CI = 1.002-1.022;p= 0.016) at 1 year. Conclusions HRV measured after admission is related to the AIS infarction basin, TOAST subtypes, and neurological outcomes at discharge suggesting a possible role for HRV in evaluating AIS and identifying high-risk patients.