Cardiac output is a key parameter in the assessment of cardiac function, and its measurement is fundamental to the diagnosis, treatment, and prognostic evaluation of all heart diseases. Until recently, cardiac output determination during exercise had been only possible through invasive methods, which were not practical in the clinical setting. Since oxygen uptake (V.O2) is cardiac output times arteriovenous content difference [C(a-v)O2)], evaluation of cardiac output is usually included its measurement.
Because of the difficulty of directly measuring peak exercise cardiac output, indirect surrogate parameters have been proposed, but with only modest clinical usefulness. Direct measurement of cardiac output can now be made by several noninvasive measurements, such as rebreathing inert gases, impedance cardiology, thoracic bioreactance, estimated continuous cardiac output (EsCCO) technology, and transthoracic echocardiography coupled to cardiopulmonary exercise testing allow more definitive results and better understanding of the underlying physiopathology.
- Vignati C, Cattadori G. Measuring Cardiac Output during Cardiopulmonary Exercise Testing. Ann Am Thorac Soc 2017 Apr 25. doi: 10.1513/AnnalsATS.201611-852FR. [Epub ahead of print] Go to PubMed