Cardiac autonomic changes after stroke

Abstract Introduction There is a highly complex and clinically important relationship between the cardiac and the nervous system, called the heart-brain axis [1]. Therefore, acute brain damage may lead to alterations in cardiac function due to changes in the autonomic nervous system[2,3]. Novel computerised biosignal analysis techniques and advanced biosignal assessment could provide a valuable tool to sensitively analyse cardiac autonomic function (CAF). CAF can be characterized by two complementary digital biomarkers, periodic repolariation dynamics (PRD) and deceleration capacity (DC). The aim of this study was to determine CAF by means of PRD and DC in patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA) and to analyze them according to their relationship with specific cardiac (high-sensitive Troponin T (hsTnT) and N-terminal pro-B-type natriuretic peptide (NT-pro BNP)) and stroke (location, type, severity) characteristics. Methoden / Methods Between February 22, 2021, and May 5, 2023, 282 patients after an AIS or TIA were enrolled in the study. During the inpatient stay, all relevant parameters were recorded and stored in a database. To assess CAF, a 30-minute biosignal measurement was performed with a high resolution (1kHz) electrocardiogram (ECG). Cardiac autonomic biomarkers, PRD and DC, were calculated semiautomatically afterwards from patients. Results Fifteen ECGs were excluded due to poor recording quality. Consequently, data from 261 AIS and 21 TIA patients were analyzed. A total of 105 patients (37.2 %) had pathological PRD (≥ 5.75 deg2) and/or DC (≤ 2.5 ms), 78 patients (27.7 %) had pathological PRD, and 57 patients (20.2 %) had pathological DC. The median PRD was 3.13 deg2 and the median DC was 5.30 ms (see Figure). There were no significant differences in the distribution of PRD and DC between male and female patients (PRD p = 0.38, DC p = 0.30), and between AIS and TIA patients (PRD p = 0.13, DC p = 0.66). Patients with middle cerebral artery (MCA) infarction had significantly higher median PRD values (3.56 deg2 [IQR 1.51 - 6.59 ] vs. 2.81 deg2 [IQR 1.15 - 5.99], p = 0.047) and lower median DC values (4.66 ms [IQR 2.65 – 7.76] vs. 6.11 ms [IQR 3.15 – 10.61], p = 0.011) than patients with stroke located in another cerebral regions (see Figure). Patients with pathological PRD or DC had significantly higher hsTnT (13.50 ng/l [IQR 9.7 – 24.1] vs. 11.05 ng/l [ IQR 7.13 – 16.23], p < 0.001) and NT-pro BNP (269.00 ng/l [IQR 117.50 – 687.00] vs. 125.50 ng/l [IQR 57.00 – 288.25], p < 0.001) values. Conclusions The study showed that a considerable proportion, more than one third of all patients, had evidence of cardiac autonomic dysfunction after acute cerebral ischaemia. Of particular interest, PRD was higher and DC was lower in patients with MCA ischaemia, reflecting a potentially higher cardiac risk profile. Cardiac autonomic dysfunction was also associated with increased hsTnT and NT-proBNP levels.