Non-invasive haemodynamic assessments using Innocor™ during standard graded exercise tests

Cardiac output (Q) and stroke volume (V (S)) represent primary determinants of cardiovascular performance and should therefore be determined for performance diagnostics purposes. Since it is unknown, whether measurements of Q and V (S) can be performed by means of Innocor during standard graded exercise tests (GXTs), and whether current GXT stages are sufficiently long for the measurements to take place, we determined Q and V (S) at an early and late point in time on submaximal 2 min GXT stages. 16 male cyclists (age 25.4 +/- 2.9 years, body mass 71.2 +/- 5.0 kg) performed three GXTs and we determined Q and V (S) after 46 and 103 s at 69, 77, and 85% peak power. We found that the rebreathings could easily be incorporated into the GXTs and that Q and V (S) remained unchanged between the two points in time on the same GXT stage (69% peak power, Q: 18.1 +/- 2.1 vs. 18.2 +/- 2.3 l min(-1), V (S): 126 +/- 18 vs. 123 +/- 21 ml; 77% peak power, Q: 20.7 +/- 2.6 vs. 21.0 +/- 2.3 l min(-1), V (S): 132 +/- 18 vs. 131 +/- 18 ml; 85% peak power, Q: 21.6 +/- 2.4 vs. 21.8 +/- 2.7 l min(-1), V (S): 131 +/- 17 vs. 131 +/- 22 ml). We conclude that Innocor may be a useful device for assessing Q and V (S) during GXTs, and that the adaptation of Q and V (S) to exercise-to-exercise transitions at moderate to high submaximal power outputs is fast enough for 1 and 2 min GXT stage durations

Validation of the use of foreign gas rebreathing method for non-invasive determination of cardiac output in heart disease patients

Objective: To compare a new device (Innocor) for non-invasive measurement of cardiac output (CO) by foreign gas rebreathing method with conventional techniques used in the measurements of cardiac function. Methods: Cardiac outputs measured by Innocor (CO(RB)) were compared with CO obtained by echocardiography (CO(EC)), Swan-Ganz thermodilution (CO(TD)), and left ventricle radiography (CO(LVR)) in 34 patients subjected to cardiac catheterization. Values obtained from the four methods were analyzed by linear regression and paired values were compared by the method of Bland and Altman in SPSS. Results: There was strong positive correlation (r=0.94) between Innocor cardiac output values and the corresponding values obtained by thermodilution and between CO(EC) and CO(LVR) values. Thermodilution appears to overestimate cardiac output when compared to the values obtained with Innocor by (0.66±0.22) L/min (P<0.0001). There was no correlation between data obtained by Innocor and the corresponding CO(EC) and CO(LVR) values. Conclusion: Innocor CO(RB) is an easy, safe and well established method for non-invasive measurement of cardiac output with good prospects for clinical application in heart disease patients