Electrical Cardiometry as a Novel Tool for Assessing Systemic Vascular Resistance and Cardiac Function in Obstructive Sleep Apnea.

Background: Obstructive sleep apnea syndrome (OSAS) is associated with sympathetic overactivity, intermittent hypoxia, and increased vascular resistance, leading to cardiovascular morbidity. Electrical cardiometry (EC) is a novel, non-invasive technology that continuously measures hemodynamic parameters such as systemic vascular resistance (SVR), systemic vascular resistance index (SVRI), cardiac output (CO), and cardiac index (CI). The aim of this study was to compare SVR and SVRI values, measured by EC, between patients with OSAS and age- and sex-matched healthy controls. Methods: In this retrospective case-control study, 70 participants were enrolled, including 33 patients with polysomnography-confirmed OSAS and 37 healthy controls matched for age and sex. All participants underwent standard EC measurement (ICON® Cardiotronics, Osypka Medical, GmbH, Berlin, Germany) under resting, supine conditions. Hemodynamic parameters such as SVR, SVRI, and CI were compared between groups. Results: EC revealed significantly higher SVR (1498.7 ± 335.6 vs. 1260.1 ± 251.5 dyn·s·cm-5, p = 0.013) and SVRI (2969.4 ± 749.1 vs. 2347.4 ± 481.0 dyn·s·cm-5·m2, p < 0.001) in patients with OSAS compared with controls, while CI was significantly lower in the OSAS group (2.6 ± 0.5 vs. 3.2 ± 0.8 L/min/m2, p < 0.001), indicating increased vascular load and reduced cardiac performance. Conclusions: This study is the first to apply EC in OSAS. EC-derived parameters, particularly SVRI and CI, effectively differentiated OSAS patients from healthy subjects, reflecting increased vascular afterload and reduced cardiac performance. These findings suggest that EC is a feasible, non-invasive tool for assessing hemodynamic alterations in OSAS and may have potential for bedside monitoring and future risk stratification studies.