Open Access
Background: Cardiac output is an important hemodynamic parameter of cardiovascular system and a significant indicator of autonomic function status of a person. It can be measured invasively as well as non-invasively. Imepdance cardiography (ICG) is a promising, new, noninvasive technique to measure cardiac output. There are no studies noninvasively measuring cardiac output in healthy subject by impedance cardiography using new horizontal method of electrode placement during postural challenges. Objective: We observed effect of postural challenges on noninvasive cardiac output measurement using ICG by new horizontal electrode placement method. Methods: Cardiac output (CO), stroke volume (SV) and cardiac index (CI), were measured non-invasively, before and after postural challenges namely Head Up Tilt (HUT) of 700 and Head Down Tilt (HDT) 200, in 38 healthy male subjects (mean age-28 yrs, range 22-34 yrs). Results: After 700 HUT the values of CO, SV and CI decreased by 1.5±0.9 l/min (31%), 25.8±11.4 ml (37%), & 0.8±0.4 l/min/m2 (27 %), respectively. HDT did not cause significant change in theses hemodynamic parameters. Conclusion: ICG successfully detected physiological changes in cardiac out following postural challenges using new horizontal electrode placement method. The study underscores utility of this simple noninvasive tool for hemodynamic assessment after postural challenge using new horizontal electrode placement method.