Experimental assessment of error sources in thermodilution measurements of cardiac output and ejection fraction

The most common method used for clinical measurement of cardiac output and right ventricular ejection fraction is thermodilution. This method is based on several assumptions, which are not always valid. This may result in errors in order of 20-50%. In this work these sources of error were experimentally examined. Results indicate that the errors associated with ejection fraction are mostly due to residual thermal energy at the right atrium that is not considered in the calculations. Cardiac output measurement suffers mostly from thermal losses along the catheter.