Background: Current noninvasive methods for estimating diastolic and mean pulmonary artery pressures (PAp) in children are cumbersome and have limited accuracy. We hypothesized that systolic PAp correlates with diastolic and mean PAp, and that this correlation can be used to estimate diastolic and mean PAp from Doppler flow data.
Methods: We recorded PAp in 112 patients 30 years or younger catheterized for heart failure, heart transplant, pulmonary hypertension, or congenital heart disease. We derived the relationship of systolic PAp to diastolic and mean PAp. We then applied these relations to systolic PAp measured by tricuspid regurgitation (TR) Doppler flow in a subset of 17 patients with pulmonary hypertension to predict mean and diastolic PAp, and correlated the results.
Results: An excellent linear relation was found between systolic PAp and both the diastolic and mean PAp measured at cardiac catheterization (r = 0.95, P < .0001; r = 0.98, P < .0001, respectively). The calculated diastolic PAp calculated from TR Doppler correlated well with invasive data (31 +/- 13 vs 30 +/- 11 mm Hg, respectively, not significant; r = 0.85, P < .0001) and surpassed existing methods that are based on pulmonary regurgitation for predicting diastolic PAp. Similarly, mean PAp calculated from TR Doppler flow correlated well with invasive data (r = 0.86, P < .0001).
Conclusion: A strong linear relationship between systolic and diastolic PAp allows for easy and accurate noninvasive estimation of diastolic and mean PAp from TR Doppler flow.