Prognostic Implications of Right-Sided Insular Damage, Cardiac Autonomic Derangement, and Arrhythmias After Acute Ischemic Stroke

Abstract

Background and Purpose— Acute stroke is associated with impairment of cardiac autonomic balance and increased incidence of arrhythmias. These abnormalities appear more relevant in the case of involvement of the right insula in the infarct area. The aim of this study was to assess the impact of right-sided insular damage, cardiac autonomic derangement, and arrhythmias on clinical outcome after acute ischemic stroke. Methods— Holter monitoring for 24 hours was performed in 208 consecutive patients with first-ever acute ischemic stroke. Time- and frequency-domain measures of heart rate variability and arrhythmias were considered in all cases. All patients were followed for a 12-month period after the initial event. Results— During the 12-month follow-up period, 48 patients died (1-year probability of death, 0.23; 95% CI, 0.17 to 0.30). Multivariate analysis demonstrated that age (hazard ratio [HR], 1.06; 95% CI, 1.01 to 1.10; P =0.0087), stroke severity on admission (HR, 1.25; 95% CI, 1.13 to 1.39; P =0.0001), presence of right-sided insular damage (HR, 2.01; 95% CI, 1.13 to 1.39; P =0.0187), as well as lower values of the SD of all normal-to-normal RR intervals (HR, 3.32; 95% CI, 1.67 to 6.24; P =0.002), and presence of nonsustained ventricular tachycardia during Holter monitoring (HR, 2.99; 95% CI, 1.58 to 5.67; P =0.0007) were independent predictors of 1-year mortality. Conclusions— The integration of traditional risk stratifiers with autonomic and arrhythmic markers, and the careful search for right-sided insular involvement, may represent an effective approach for identification of stroke patients at risk for early mortality.