Autonomic nervous system dysfunction in advanced systolic heart failure

BackgroundAn alteration of the autonomic nervous system has been described in heart failure (HF). The aim of this study was to assess, compare and relate the impairment of both arms of the autonomic nervous systems, the sympathetic and parasympathetic (SNS and PNS) in a same group of patients.MethodsWe analyzed 23 patients with advanced HF (NYHA III-IV/IV and IV/IV) and EF < 35% who were on the waiting list for heart transplantation. We assessed the SNS by determining cardiac uptake of 123I metaiodobenzylguanidine, and analyzed the heart mediastinum rate (HMR) and the myocardial washout rate (WR). The PNS was assessed by 24-hour Holter ECG recording and subsequent analyses of heart rate turbulence (HRT) in which turbulence onset (TO) and turbulence slope (TS) were determined.ResultsIn the study of the SNS, HMR values were1.32 ± 0.12, and WR 0.36 ± 0.1. Higher creatinine levels were associated with a lower WR (r = −0.604; p = 0.02). In the study of the SNP, TO was higher the lower the LVEF (r = −0.410; p = 0.052), and age was associated with a lower TS (r = −0.4; p = 0.059). In the study of the relationships between the SNS and PNS, HMR was correlated in a nearly significant manner with TO (r = −0.399; p = 0.059) and WR with TS (r = −0.447; p = 0.033).ConclusionsIn stable patients with advanced HF (NYHA III-IV and IV/IV), a significant and parallel impairment occurs in both arms of the autonomic nervous system. This could have prognostic implications and would help to prioritize patients on the waiting list for heart transplantation.