Confict of interest: none declared. Submitted: December 20, 2016. Accepted: February 26, 2017. * Corresponding author: Department of Cardiology, Medical University of Bialystok, ul. Curie‑Sklodowskiej 24a, 15‑276 Bialystok, Poland;e‑mail: fzklin@wp.pl; tel: 857 468 656; fax: 857 467 604 Copyright © 2016 Journal of Rare Cardiovascular Diseases; Fundacja Dla Serca w Krakowie Abstract Background: Electrical cardiometry (EC) technique could estimate cardiac output (CO), cardiac index (CI) and other parameters related to cardiac contractility and fuid status by measuring the thoracic electrical bioimpedance. We hypothesized that EC could assess right ventricle (RV) hemodynamic function in patients diagnosed with pulmonary arterial hypertension (PAH). Results: In our pilot study, enrolling 23 PAH patients, we observed a signifcant correlation (r = 0.71; p <0.001) between thermodilution CO measurement results (4.59 ±1.05 l/min) and CO results obtained by EC (4.86 ±1.20 l/min) and between systemic vascular resistance calculated by EC monitor and obtained during right heart catheterization (RHC) (r = 0.68; p = 0.002). Furthermore, EC parameter index of contractility (ICON) sig‑ nifcantly correlated with tricuspid annular plane systolic excursion assessed by echocardiography (r = 0.57; p = 0.01). Conclusions: RHC cannot be replaced in obtaining accurate results of CO, however EC technique provides feasible insight into RV function at the bedside or outpatient care. JRCD 2017; 3 (2): 44–49 Key words: rare disease, electrical cardiometry, right heart catheterization, pulmonary arterial hypertension, hemodynamic measurements The pilot study of role of electrical cardiometry in non‑invasive assessment of hemodynamic parameters in patients with pulmonary arterial hypertension (RCD code: II‑1A.1) Remigiusz Kazimierczyk 1 , Małgorzata Jasiewicz 2 , Marta Marcinkiewicz‑Siemion 1 , Małgorzata Knapp 1 , Anna Lisowska 1 , Piotr Błaszczak 3 , Bożena Sobkowicz 1 , Włodzimierz J. Musial 1 , Ryszard Grzywna 3 , Karol A. Kamiński 1,4 * 1  Department of Cardiology, Medical University of Bialystok, Poland; 2  Department of Cardiology and Internal Diseases, Jurasz University Hospital No 1, Bydgoszcz, Poland; 3  Department of Cardiology, Cardinal Wyszynski Hospital, Lublin, Poland; 4  Department of Population Medicine and Civilization Diseases Prevention, Medical University of Bialystok, Poland ORIGINAL PAPER Rare diseases of pulmonary circulation Journal of Rare Cardiovascular Diseases 2017; 3 (2): 44–49 www.jrcd.eu Background Te electrical cardiometry (EC) technique could estimate cardiac output (CO), cardiac index (CI) and other parameters related to cardiac contractility and fuid status by measuring the thoracic electrical bioimpedance [1]. It has been validated and is utilized in various cardiovascular disorders, however its diagnostic rele‑ vance in patients with pulmonary arterial hypertension (PAH) or right ventricular (RV) failure is unclear [2]. In PAH patients, RV failure is a very common cause of deterioration of patients’ status and ofen leads to death. CI, assessed by thermodilution method during right heart catheterisation (RHC), belongs to the most im‑ portant parameters describing the clinical status. According to the 2015 Te European Society of Cardiology (ESC) / European Respiratory Society (ERS) guidelines, patients with CI lower than 2 litres/min/m 2  are in high risk (>10%) of 1‑year mortality [3]. EC could be an opportunity to assess hemodynamic state of patient in a non‑invasive way. Based on changes of thoracic electrical bioimpedance during the cardiac cycle and on the input of body mass, EC estimates stroke volume (SV). Te model of EC assumes that the alignment of erythrocytes in the aorta is responsible for a signifcant change in the impedance afer the aortic valve opening and relies on a change in impedance dependent on the blood fow in the aorta. Ten a mean velocity index is empirically derived from a peak ampli‑ tude measurement assumed to be an index of peak aortic accelera‑