Comparison of Doppler-determined elevated pulmonary arterial pressure with pressure measured at cardiac...

This study assesses use of pulsed Doppler echocardiography to measure pulmonary artery (PA) pressure. PA flow at the right ventricular (RV) outflow tract was analyzed in 51 patients. Attention was focused on PA flow morphologic pattern, RV systolic intervals, time to peak flow and acceleration time index. Correlation was made with PA pressure and total pulmonary resistance. Three morphologic patterns of PA flow were found: type I indicates normal PA pressure (sensitivity 85%, specificity 100%) and types II and III indicate PA hypertension (sensitivity 100%, specificity 85%). The RV preejection/RV ejection ratio, time to peak flow and acceleration time index show a good correlation coefficient improved when a logarithmic function was applied. The best correlation was achieved with time to peak flow (r = -0.77 with PA pressure, r = -0.79 with total pulmonary resistance), and especially with acceleration time index (r = -0.84 with PA pressure, r = -0.87 with total pulmonary resistance). Analysis of pulmonary flow is a reliable new tool for evaluating PA pressure and is even better for evaluating total pulmonary resistance. Acceleration time index is the parameter that correlates best with these 2 variables.