Cardiac output measured by electric bioimpedance compared with the CO2 rebreathing technique at different exercise levels.

In the lower range of cardiac output (CO, up to 15 l min-1), we found an excellent agreement between CO measured by bioimpedance and carbon dioxide rebreathing techniques. CO estimated by bioimpedance was generally lower. The bioimpedance method had better reproducibility. Both methods seem valuable for non-invasive studies in healthy subjects at work.