P144 ASCENDING AND DESCENDING THORACIC AORTA PU-LOOPS FOR THE ESTIMATION OF LEFT VENTRICULAR AFTERLOAD

Introduction: Pressure-Velocity (PU) loops obtained in the descending thoracic aorta (PU-loopsdes) could estimate left ventricular afterload with two remarkable angles: β and GALA (Global Afterload Angle) [1].The aim of this study is to compare PU-loops measured in the ascending aorta (PU-loopsasc) versus PU-loopsdes. Methods: This study was conducted in patients scheduled for elective interventional neuroradiology. During the procedure, we measured pressures at two different sites:(1) in the ascending aorta where we obtained a transthoracic echocardiogram (TEE) concomitantly to measure ascending aortic blood velocity, (2) in the descending thoracic aorta where blood velocity was obtained using a trans-esophageal Doppler probe. Patients were divided into high risk (HR) and low risk (LR) groups based on their cardiovascular risk factors. Results: Twenty five patients were included (13 HR, 12 LR). We observed a significant increase in both β and GALA angles between PU-loopsasc and PU-loopsdes (from 7° [0–15] to 13° [5–20] and from 30° [23–37] to 41° [29–54], p < 0.01 respectively). This increase was more marked in the HR group compared to the LR group (p < 0.05) (Fig 1). Just like in PU-loopsdes, we found that β and GALA angles in PU-loopsasc could also discriminate between LR and HR patients (3° [0.4–6] vs 17° [9–25] and 24° [22–26] vs 38° [34–43], p < 0.01 respectively). Conclusion: PU-loopsasc had lower β and GALA angles compared to PU-loopsdes. However, GALA could discriminate between high and low cardiovascular risk patients in both sites.