Onset Time of Retrograde Flow in the Pulmonary Artery in Pulmonary Arterial Hypertension Patients: An Estimator for Pulmonary Arterial Pressure?

Frank Helderman¹, Gert Jan Mauritz¹, J. Tim Marcus¹, Kirsten Andringa¹, Nico Westerhof¹, Anton Vonk Noordegraaf¹

The objective was to assess if mean pulmonary artery pressure (mPAP) could be estimated using a standard 2D MR phase-contrast velocity quantification in the main pulmonary artery. Included were 37 Pulmonary Arterial Hypertension (PAH) patients vs 8 controls. Onset time of the retrograde flow (Retrograde Onset Time = ROT) as fraction of cardiac cycle time, and cross sectional area (CSA) of the main pulmonary artery were measured. Regression analysis revealed an association between mPAP and ROT (r=0.74; p<0.001), and between mPAP and CSA (r=0.68; p<0.001). The early retrograde flow in PAH is explained with a recirculation zone.