ABSTRACT
Impedance cardiography Impedance cardiography, or thoracic bioimpedance, is a form of plethysmography that uses changes in thoracic electrical impedance to estimate haemodynamic parameters such as cardiac output and thoracic fluid content (244). Some studies have suggested that the use of impedance cardiography in combination with assessment of brain natriuretic peptide (BNP) might aid diagnosis of HF in the emergency setting. More recently, implantable impedance monitors (combined with pacemaker defibrillator devices) have been developed, with the aim of early detection of impending decompensation by measuring trends in thoracic fluid content, with a view to prevention of the development of clinical decompensation and hospital admission. Large scale trials will be necessary to determine if such devices can prevent admissions and improve quality of life in patients with advanced HF.
