RT Journal Article SR Electronic T1 139 Reduced Aortic Distensibility and Adverse Cardiovascular Functional Performance in Adult Patients with Single Ventricular Physiology JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP A80 OP A81 DO 10.1136/heartjnl-2015-308066.139 VO 101 IS Suppl 4 A1 Nicola Edwards A1 Mengshi Yuan A1 Sarah Bowater A1 Paul Clift A1 Sara Thorne A1 Lucy Hudsmith YR 2015 UL http://heart.bmj.com/content/101/Suppl_4/A80.abstract AB Introduction Children with reconstructed aortas performed for palliation in hypoplastic left heart syndrome (HLHS) have reduced aortic distensibility and unfavourable arterial-ventricular coupling. The impact of these changes on ventricular function and cardiovascular functional performance in surviving adults with single ventricular physiology remains unknown.Methods Cardiac MRI (1.5T) was performed in 10 patients (mean age 19 years ± 2) with HLHS who had undergone aortic reconstruction in childhood, 10 age and gender matched patients with single ventricle physiology but without aortic reconstruction and 10 age and gender matched diabetic controls subjects. Aortic distensibility (defined as (maximum aortic area – minimum aortic area/minimum aortic area)/pulse pressure)) was assessed in the mid ascending aorta throughout the cardiac cycle using steady state free precession imaging and analysed using Matlab software. Congenital patients also underwent routine cardiopulmonary exercise testing (RAMP protocol) to asses parameters of cardiovascular functional performance.Results Patients with HLHS had reduced aortic distensibility compared with patients with single ventricular physiology and diabetics (2.13 10–3 mmHg ± 1.26 vs. 3.9 10–3 mmHg ± 1.41 vs. 7.3 10–3 mmHg ± 1.38, p < 0.01) Figure 1. There were no differences in univentricular volumes or ejection fraction between HLHS and other single ventricular physiology (EF 55% ± 8 vs. 60 ± 5, p = 0.12). All patients with single ventricular physiology had marked cardiac limitation. Functional restriction was more severe in HLHS although did not reach statistical significance; predicted VO2 max for age and gender 55% ± 18 vs. 60% ± 20 (p = 0.16), reduced cardiac work load 9.27 METS ± 3.6 vs. 10.4 METS ± 3.5 (p = 0.47), VE/VCO2 slope < 35 n = 6 vs. n = 3 (p = 0.68).Abstract 139 Figure 1 Box scatter plot of aortic distensibility in patients with single ventricular physiology compared with matched diabetic subjectsConclusion Adults with reconstructed aortas in hypoplastic left heart syndrome have reduced aortic distensibility and impaired prognostic markers of functional cardiovascular performance before changes in ejection fraction. The potential impact of these findings warrants further study.