Figure 1

A schematic illustration of the basic features of the RV pressure waveform (Top) and the identification of these feature points using the first derivative, dP/dt, of the RV pressure waveform (Middle). Three of these points identify the turning points of the RV outflow waveform approximated as a triangle (Bottom). The vertices of the flow waveform correspond to time of dP/dt_max, peak flow (Q_max )= time to early systolic shoulder of the RV pressure waveform (P_1st), the time of dP/dt_min. Hence, the triangle inscribed in the RV pressure waveform corresponds to the approximated RV outflow waveform. The ejection duration (ED) is defined as the difference between time of dP/dt_max and time of dP/dt_min, P_es is the pressure at the time of dP/dt_min. The RV diastolic pressure (RVDP) is measured at the time of the R-wave from the electrogram (EGM).