A comprehensive meta-analytic review of the neurophysiological properties of the heartbeat evoked potential in health and disease

BACKGROUND: The heartbeat evoked potential (HEP) is an electrophysiological indicator of cortical processing of cardiac signals and a putative neural index of cardiac interoception. Various clinical conditions are associated with disrupted heart-brain communication, raising the possibility that the HEP could serve as a valid biomarker of disrupted cardiac interoception. Yet there is limited understanding about how the HEP signal, and its various parameters, is associated with different health conditions. METHODS: We synthesised the current evidence for HEP amplitude as a biomarker across all available clinical subpopulations using a random-effects multilevel meta-analysis. Secondly, we systematically characterised and quantitatively evaluated key HEP parameters, such as latency windows, reference electrodes, and scalp topographies across HEP studies (OSF Doi: 10.17605/OSF.IO/TMQ3W). RESULTS: Subgroup analyses for each condition showed no difference in HEP amplitude between clinical conditions relative to healthy comparisons; however, large negative effect estimates were found in neurological and cardiovascular diseases, though these were based on a small number of studies and should be interpreted with caution. In subsequent multivariate analysis, clinical category partially explained the global variability in HEP parameters. CONCLUSIONS: Based on these results, no firm conclusions can be drawn regarding the utility of HEP amplitude as a clinical biomarker. Substantial heterogeneity and widespread methodological inconsistencies across studies preclude definitive interpretations, and rigorous, standardised research is needed before the clinical value of HEP can be established.