Applicability of Impedance Cardiography During Heart Failure Flare-Ups

BACKGROUND Heart failure (HF) accounts for about 5% of all causes of urgent hospital admissions, and the overall mortality of HF patients within 1 year after hospitalization is 17-45%. Transthoracic impedance cardiography (ICG) is a safe, non-invasive diagnostic technique that helps to detect various parameters that define different cardiac functions. The aim of this study was to investigate the value of ICG parameters in patients hospitalized due to HF flare-ups. MATERIAL AND METHODS The study included 60 patients (24 women and 36 men) who were admitted to intensive care units because of an acute episode of HF without signs of myocardial infarction. The diagnosis of HF as the main reason for hospitalization was verified according to the universally accepted techniques. ICG data were compared to those obtained via other HF diagnostic techniques. RESULTS A moderately strong relationship was found between the ejection fraction (EF) and the systolic time ratio (STR) r=-0.4 (p=0.002). Findings for STR and thoracic fluid content index (TFCI) differed after dividing the subjects into groups according to the EF (p<0.05). A moderately strong relationship was found between brain natriuretic peptide and TFCI r=0.425 (p=0.001), left cardiac work index (LCWI) r=-0.414 (p=0.001). Findings for TFCI, LCWI, and cardiac output differed after dividing the subjects into groups according to HF NYHA classes (p<0.05). CONCLUSIONS Transthoracic impedance cardiography parameters could be applied for the diagnostics and monitoring of HF, but further studies are required to evaluate the associations between ICG findings and HF.