Heart rate variability of acute ischemic stroke patients according to troponin levels

Abstract

Objective: Neurogenic myocardial stunning is a type of stress-induced cardiomyopathy thought to be a result of dysregulation of the autonomic nervous system. Heart rate variability (HRV) analysis is a potential method for understanding the underlying mechanisms of autonomic dysfunction in ischemic stroke. The aim of the study was to investigate HRV in stroke patients in accordance with troponin levels. Patients and Methods: Sixty-six patients (mean age 65 ± 13 years; 39 male) presenting with acute ischemic stroke were consecutively included. High-sensitive cardiac troponin I (hs-cTnI) levels were accepted as elevated when> 0.04 ng/mL. All patients underwent ambulatory electrocardiographic (ECG) monitoring within the first seven days to obtain time-domain and frequency-domain measures of HRV. Results: Twenty patients (30.3 %) had elevated hs-cTnI. Patients with high troponin levels had significantly lower left ventricular ejection fraction (LVEF), higher ST-segment-T wave changes, and higher N terminal pro-brain natriuretic peptide (NT-proBNP) levels. Low-frequency/high-frequency (LF/HF) value was significantly higher in the troponin-positive group, but other ambulatory ECG monitoring parameters such as SDNN, SDANN, RMSSD, and pNN50 were similar among patients. Conclusion: Neurogenic myocardial damage presenting with high troponin levels can be seen in ischemic stroke patients and may be associated with sympathetic overactivity.