Whether the peak rate of pressure rise (dP/dtmax) in peripheral arteries is influenced by left ventricular (LV) contractility or by loading conditions remains controversial. We, therefore, appreciate the letter by Monge-García et al.[1] and have read it with interest. Our colleagues challenge the use of LV ejection fraction (LVEF) as a marker of LV systolic function and its comparison with femoral dP/dtmax to assess the reliability of the femoral dP/dtmax to track changes in LV contractility [1]. We entirely agree that LVEF is not a pure marker of LV contractility, as widely documented by others [2], and as clearly acknowledged in the discussion section of our article [3]. Furthermore, we agree that the invasive measure, LV end-systolic elastance (Ees), is the gold standard methodology to estimate LV contractility, but we were unable to measure it for ethical and technical reasons. In our paper [3], we presented LVEF data, as is commonly done in similar studies, but in contrast to the inference of our colleagues’ letter [1], our conclusion was not based upon LVEF results.

In our study [3], we measured femoral dP/dtmax by pulse contour analysis before and after varying, LV systolic function (dobutamine infusion), preload (volume expansion and passive leg-raising) and afterload (norepinephrine) in 19 critically ill patients with cardiovascular failure [3]. Femoral dP/dtmax changed, not only in response to dobutamine infusion, but also following changes in cardiac loading, particularly following changes in afterload induced by variations in