Comprehensive non-invasive cardiac and autonomic assessment in acute ischemic stroke patients: a pilot study.

Background: The aim of this study was to comprehensively determine hemodynamic and autonomic responses during-head up tilt test (HUT) in the acute and recovery phase of ischemic stroke.

Methods: Cardiovascular parameters, baroreflex sensitivity (BRS), spectral-indices of heart rate (HRV), systolic (sBPV) and diastolic blood pressure variability (dBPV) were measured at rest in ischemic stroke patients (N.=17) and control group (N.=34). Dynamic cardiac autonomic function was assessed using HUT (Delta [rest-tilt]. Controls were examined once whereas stroke group at two timepoints: on admission and in day 10 (recovery period).

Results: After a recovery period the stroke group showed significantly higher resting values of systolic blood pressure (sBP, P=0.028), systolic time ratio (STR, P=0.023), high frequency sBPV (HF-sBP, P=0.027), high frequency R-R interval (HF-RRI, P=0.048), power spectral density of sBPV (PSD-sBP, P=0.004) and lower sympathovagal ratio (LF/HF, P=0.005), low frequency R-R interval (LF-RRI, P=0.045), BRS and significantly lower increase in post tilt changes in systolic blood pressure (Delta sBP), total peripheral resistance (Delta TPR) compared to controls. No significant differences were observed for post-tilt in all hemodynamic changes compared to admission. After the recovery period the patient group showed an improved blood pressure profile, left ventricular work index, systolic time ratio and BRS compared to admission.

Conclusions: Patients with acute ischemic stroke after a recovery period presented autonomic imbalance and impaired cardiac sympathetic modulation at rest and in response to orthostatic challenge compared to a control group. Furthermore, there was a statistically significant decrease in baroreflex sensitivity, suggesting parasympathetic deficiency.