Sacchi S, et al. - Regarding Doppler assessment of aortic stenosis, the reproducibility of peak and velocity time integral (VTI) measurements across a much larger group of operators was investigated in this study, using custom-designed software which stored operators’ traces. Researchers also explored the mechanisms by which disagreement arose. They found that compared with the VTI, measuring the peak of a Doppler trace was far more reproducible as well as reduced measurement variance by approximately 6-fold. Since tracing the steep slopes in the early and late part of the VTI envelope was difficult to achieve reproducibly, peak measurements were considered superior to VTI.