Stroke volume estimation using electrical impedance tomography: a systematic review of preclinical and clinical studies

Transthoracic echocardiography and cardiac magnetic resonance can accurately determine stroke volume (SV), however, both require specialized expertise and infrastructure for analysis and interpretation. Electrical impedance tomography (EIT) has emerged as a non-invasive imaging modality that still requires appropriate training and equipment, but that can be implemented with comparatively simpler training and acquisition protocols. While EIT has been applied clinically for pulmonary assessment, it remains unestablished for cardiac applications. We performed a systematic review according to PRISMA 2020 guidelines and the Cochrane Handbook for Systematic Reviews to determine the performance of cardiac EIT in estimating SV (PROSPERO #CRD420251155255). PubMed and Google Scholar were queried from inception to October 31, 2025. Nine human studies included feasibility, simulation, physiological observational, and reference-comparison designs. Among studies incorporating independent reference measurements, cardiac EIT exhibited moderate correlation with established methods ( R 2 up to 0.74). Similarly, eight porcine studies exhibited a wide range of correlations between EIT-derived and invasive SV estimates ( R 2 = 0.34–0.96). Risk of bias assessed using the QUADAS-2 tool was low across studies; applicability and generalizability can be improved with wider patient selection. Cardiac EIT can track relative SV changes with reasonable reproducibility compared with reference assessments.