Serial Hemodynamic and Autonomic Changes in Acute Ischemic Stroke: Relation to Outcome, Stroke Type, and Location

Abstract

Background: Hypertension and changes in autonomic functions commonly accompany the acute phase of ischemic stroke and are recognized to influence outcomes. Few studies have addressed hemodynamic and autonomic monitoring together in acute stroke. Aim: We aimed to study serial hemodynamic and cardiovascular autonomic changes among patients with acute ischemic stroke (AIS) using thoracic electrical bioimpedance and to explore their relation to stroke outcome, stroke type, location, and severity. Methods: Patients with AIS of <96 h duration underwent serial hemodynamic/autonomic function studies over the first 4 days of admission. Their association with stroke severity, type, location, and outcome was explored using univariate and multivariate analyses. Patients with arrhythmias, pulmonary edema, or cardiac failure were excluded. Results: Of the 55 patients (M:F::27:28; age: 62 + 12 yrs) with AIS, 33 had large artery stroke, 18-lacunar and 4-cardioembolic stroke, and 6 died. Mean blood pressure, systemic vascular resistance (SVR), and cardiac output (CO) decreased over 4 days. Several hemodynamic and autonomic parameters correlated with the outcome on univariate analysis, while CO and SVR independently predicted the outcome. Stroke type was related to few hemodynamic parameters (SI, cardiac index on days 2-4). Lacunar stroke type was associated with left ventricular ejection time and low-frequency/high-frequency ratio (P < .05). Conclusion: Among patients with AIS, early sympathetic autonomic dominance may explain decreasing hemodynamic trends observed over the initial 4 days. 2 hemodynamic parameters, CO and SVR, independently predicted stroke outcome, while blood pressure did not. Further studies are indicated to explore the possibility of influencing stroke outcomes through modification of CO or SVR.