A new modality for the estimation of corrected flow time via electrocardiography as an alternative to Doppler ultrasonography.

ABSTRACT

BACKGROUND: Evaluation of corrected flow time (FTc) via ultrasonography is one of the suggested modalities for the assessment of intravascular volume status. This study aimed to compare the results of FTc of carotid artery measured via ultrasonography, as a measure of mechanical outcome of the cardiac cycle, with the results of FTc estimation from a new modified formula via electrocardiography (ECG), as a measure of electrical function of the cardiac cycle. METHODS: Healthy volunteers were evaluated before and after a passive leg raising (PLR) maneuver. FTc was measured concurrently before and after PLR via a modified method from ECG and via ultrasonography of the carotid artery. RESULTS: A total number of 98 healthy volunteers (51 women and 47 men) with a mean age of 30.69 ± 6.28 years were included. There was a significant correlation between FTc measured by ultrasonography and estimated by ECG both before PLR and after PLR (r = .878, p < .0001 and r = .797, p < .0001, respectively). Changes in FTc were slightly higher in measurements by ultrasonography compared to estimations by ECG (22.33 ± 17.15 ms0.5 vs. 15.86 ± 14.25 ms0.5 , p = .001). CONCLUSION: Estimation of FTc via ECG is potentially an effective and feasible method for the assessment of volume status at the clinical settings. Further investigations should determine the significance of differences that may be observed between ultrasonography and ECG in patients with either dehydration or volume overload and in the need of real-time volume status assessment.