dP/dt max - A measure of 'baroinometry'

摘要

dP/dt max is the maximal rate of rise of (usually) left ventricular pressure (LVP), but it is determined by myocardial contractility and the loading conditions on the ventricle, thus it is an imperfect and sometimes incorrect predictor of the inotropic state (myocardial contractility). The value of dP/dt max to represent contractility may be improved by adjusting it to ventricular end-diastolic volume (pre-load) or by calculating dP/dt as a function of LVP during isovolumetric contraction and determining the maximal value. Every investigator who uses dP/dt max should record this parameter while venous return is changed in order to observe how dependent dP/dt max is on pre-load. Since dP/dt max does not represent only the inotropic state, we coined the term baroinometry to represent that dP/dt max is determined by aortic pressure (baro), the inotropic state (ino), and the length (meter). dP/dt max measures the inotropic state only when loading conditions are unchanged.