Non-invasive cardiovascular profiling using combined electrocardiogram-Doppler ultrasonography and impedance cardiography: An experimental approach

In the present study, the feasibility of cardiovascular profiling using both combined electrocardiogram (ECG)-Doppler ultrasonography and impedance cardiography (ICG) was evaluated. Fourteen non-pregnant healthy women received 500mL saline solution (NaCl 0.9% at 999mL/h) intravenously by steady state infusion. Before and after this acute volume loading, we measured orthostatic-challenged cardiac and arterial characteristics using ICG and assessed venous characteristics by combined ECG-Doppler before and during the Valsalva manoeuvre. Changes are expressed as the mean +/- SEM and were evaluated by the one-sample Wilcoxon signed-rank test. After volume loading, the observed fall in stroke volume after postural change from supine to standing decreased (-14 +/- 3 vs -23 +/- 2%; P=0.011). Hepatic A wave velocity increased 63 +/- 28% after volume loading (P=0.007) and decreased during the Valsalva manoeuvre (-205 +/- 21%; P=0.001). Volume loading raised the thoracic fluid content index in both the supine and standing positions (7 +/- 2% and 10 +/- 1%, respectively; P0.014). Combined ECG-Doppler ultrasonography and ICG enables the non-invasive identification of concomitant haemodynamic changes at the level of the heart, the arterial bed and the venous compartment. Our data support the view that non-invasive cardiovascular profiling is feasible, which seems particularly useful for the evaluation of patients who are not critically ill, such as pregnant women.