In their further comment, Drs. Fisher and Hassoun have calculated mPAP by using the standard formula (mPAP = 2/3 dPAP + 1/3 sPAP; where dPAP is diastolic PAP), and we obtain roughly similar results (bias = − 1.4 mm Hg; 95% limits of agreement, – 4.1 to 1.3 mm Hg). They conclude that “the standard formula is easier and arguably more accurate,” and our reply will discriminate practical from physiologic considerations. From a practical point of view, there is no need of any formula in the catheterization laboratory, as mPAP is automatically integrated over time by the computer system. Conversely, we feel that our formula is easier to use than the standard one in the echo-Doppler laboratory, where precise measurements of dPAP are not always available, whereas more reliable measurements of sPAP are often obtained. Furthermore, our formula was less biased (and thus more accurate) than the empirical formula, which was, however, more precise as evidenced by the narrower 95% limits of agreement.