Abstract 17273: Real Time Magnetic Resonance Assessment of Septal Curvature Accurately Tracks acute changes in Hemodynamics in Paediatric Pulmonary Hypertension
Objectives: Septal curvature (SC) assessed with MRI can be used to assess pulmonary artery pressure (PAP) in pulmonary hypertension. We hypothesized that this technique could be used to track acute changes in pulmonary hemodynamics that are important in therapeutic decision-making.
Methods: 45 paediatric pulmonary hypertension patients (mean age =7.5±0.7) underwent combined cardiac catheterization and MRI. Pulmonary vascular resistance (PVR) was calculated using phase contrast flow and simultaneously acquired invasive PAP and wedge pressure at baseline and during vasodilation (100% 02 and 20ppm NO). SC was measured in short axis cine images at papillary muscle level using real time k-t SENSE. SC was also measured in 20 age matched unsedated normal controls.
Results: Baseline mean PAP was 44±1.8mmHg, Qp was 3.4±0.17 l/min and PVR was 11.7±0.9 WU. Baseline SC in patients was -0.12±0.05 compared to 1.02 ±0.05 in normal controls with no overlap. SC was strongly negatively correlated with mean PAP and PVR at baseline (r=-0.78 r=-0.82 P<0.01 respectively) and during vasodilation (r=-0.77 r=-0.87 P <0.01 respectively). Change in SC during vasodilation also correlated with change in mean PAP and PVR (r=0.42, r=0.57 P<0.05). Furthermore, a change in SC of 0.24 predicted a 20% fall in PVR with a sensitivity of 89% and a specificity of 78%.
Conclusions: Tracking changes in pulmonary hypertension hemodynamics is useful when assessing disease progression and response to therapy. We have shown that SC correlates not only with PAP and PVR but also change in these parameters during vasodilation. This suggests that SC could be used for continuing assessment of load in pulmonary hypertension, minimizing the need to repeat invasive PVR studies. It could also be used to identify pulmonary hypertension as there was no overlap in SC between patients and controls. Furthermore, the use of real-time MRI allows this technique to be used routinely in unsedated children without breathholding.
- © 2013 by American Heart Association, Inc.