Figure 2: Selected echocardiographic signals and indices used to measure right ventricular function and pulmonary flow. Section A shows tricuspid annular plane systolic excursion (TAPSE) in a patient with preserved RV systolic function. Section B shows a tissue-Doppler signal of the proximal right ventricular wall; isovolumic acceleration is measured as the maximal isovolumic velocity divided by the time to peak isovolumic velocity; e is the maximal early diastolic velocity and a represents the maximal late or atrial associated velocity. Section C shows a pulmonary flow signal; a notch is present and usually indicates decreased pulmonary compliance and altered reflection waves. Section D shows a tricuspid regurgitation signal. Both the pulmonary ejection time and the tricuspid regurgitation time are used to measure the right ventricular myocardial performance index (RVMPI).