Abstract 12945: A Novel Index for Quantification of Interventricular Septal Flattening in Pediatric Patients With Right Ventricular Hypertension
Introduction: Systolic flattening of the inter-ventricular septum (IVS) is a marker of elevated right ventricular pressure (RVp). It can be non-invasively quantified by a left ventricular eccentricity index (LVEI), RV to left ventricular (LV) ratio and a novel index - the systolic flattening angle (SFA). Data evaluating the relationship between these indices and invasive RVp in pediatrics are limited.
Methods: Patients referred for right and left heart cardiac catheterizations (CC) were enrolled and underwent echocardiograms after induction of anesthesia. The SFA, RV:LV ratio and LVEI were measured in end-systole. Peak systolic RVp and aortic pressure (pAo) were measured simultaneously during CC. The likelihood of SFA to predict an RVp:pAo ratio of > 0.5 was assessed using receiver-operator curve (ROC) analysis. Bland-Altman plots were used to assess inter-observer agreement.
Results: Forty-one unique subjects were enrolled [56% female, median age 2.7 years (0.7, 7.1) and median weight 12.1kg (6.0, 22.3)]. The median mid-ventricular (MV), apical, and sub-costal LVEI was 1.18 (0.9, 1.7), 1.18 (1.0, 1.7), and 1.13 (1.0, 1.5), respectively. The mean SFA was 8.5±9.6°, the median RV:LV ratio was 0.71 (0.46, 1.23), and the mean RVp:pAo ratio was 0.68 ± 0.5. There was a significant negative correlation (r = -0.75, p <0.001) between SFA and RVp:pAo ratio and a modest correlation with other non-invasive indices (Figure). ROC analysis demonstrated an area under the curve = 0.90 for prediction of RVp:pAo > 0.50 by SFA. An SFA < 10.6 had a sensitivity of 88% and specificity of 79% in predicting RVp:pAo > 0.50. SFA was modestly reproducible with a Bland-Altman plot demonstrating a bias of 4.14 and limits of agreement of -7.8 and 16.1.
Conclusions: SFA has the best correlation with RVp:pAO, good sensitivity and specificity, but relatively high inter-observer variability. Taken together, these non-invasive measures may help minimize the need for invasive assessment of RVp.
Author Disclosures: K. Averin: None. E. Michelfelder: None. L. Urbinelli: None. R. Hirsch: None.
- © 2016 by American Heart Association, Inc.