bjectives.– To evaluate the feasibility at rest with reproducibility of the ntra-operator and inter-operator measurement of CO and to compare with easurements obtained by transthoracic echocardiography (TTE). To estimate he feasibility during effort and during the recovery effort. To determine the iagnostic, therapeutic and prospective implication. ethods.– Observational study based on 142 consecutive outpatients included rom cardiac rehabilitation (CHU Dijon). IGR was performed before and/or uring and/or after the cardiac stress test by photoacoustic analysis using two nert gases: 0.5% nitrous oxide and 0.1% sulfur hexafluoride (indirect oxyen Fick Method Innocor®). Statistical analysis based on correlation analysis, land and Altman, and standardization. esults.– At rest, the correlation coefficient was 0.91 (P< 0.001) between two O in intra-operator in 26 patients, 0.89 (P< 0.001) between two CO in interperator in 30 patients, 0.38 (P= 0.039) between the CO measured by IGR and TE in 30 patients. Using the method of Bland and Altman, the range of variation f repeatability was respectively± 27%, ± 33%± 42%. During the effort in 45 atients, formulas of standardization were used to assess components: stroke olume (SV) and heart rate (HR). Two populations were isolated: preferential ncrease in SV or HR. onclusion.– At rest, feasibility, repeatability and reproducibility of the meaurements are correct (despite the dispersion related to measurement of CO). t submaximal exercise, feasibility is good. The measurement to quantify the emodynamic changes during rehabilitation is valid and applicable in various athological conditions (heart failure in high CO at rest, etc), and could help to dapt the use of chronotopic drug. eferences 1] Goda A et al. Usefulness of non-invasive measurement of cardiac output uring sub-maximal exercise to predict outcome in patients with chronic heart ailure. AM J Cardiol 2009; 104(Suppl. 11):1556–60. 2] Follath F. Challenging the dogma of high target doses in the treatment of eart failure: is more always better? Arch Cardiovasc Dis 2009;102:785–9.