Abstract 15606: Left Ventricle Function and Sympathetic Innervation in Type 1 Diabetes
Objective: In type 1 diabetes (T1DM) alterations in left ventricle (LV) function may occur without clinical evidence of other complications, possibly due to sympathetic activation and/or alterations in myocardial oxidative metabolism and efficiency. We evaluated the association between LV sympathetic innervation and LV function in patients with T1DM with no evidence of coronary artery disease.
Methods: Cross-sectional study in 16 subjects with T1DM, 37% females, mean age 35±14 years, diabetes duration 12±6 years, mean HbA1c 7.9±1.3. LV sympathetic innervation was assessed by positron emission tomography (PET) with [11C]meta-hydroxyephedrine ([11C]HED), myocardial efficiency expressed as Work-Metabolic Index (WMI)was assessed by [11C]acetate PET and magnetic resonance imaging (MR), and changes in LV function were assessed by conventional and tagged MR acquired on 3T wide-bore 70cm “Ingenia” system (Philips Medical Systems, Best, The Netherlands). Tagged MRI were acquired using a modified FFE sequence with grid tagging. Regional LV torsion was assessed using HARP software (Diagnosoft, Cary, NC, USA) and compared with regional LV sympathetic innervation.
Results: In these subjects mean end-diastolic volume (EDV) was 72.6 ml/m2, mean LV mass was 50.9 g/m2, LV mass/EDV ratio 0.7, and mean ejection fraction was 61.4% all normalized by body surface area. WMI ranged from 1.01 x 107- 5.2x106 mmHg/ml/m2. The global LV [11C]HED “retention index” (RI) was similar with age-matched healthy controls. Coregistration of regional [11C]HED and LV torsion shows higher torsional angle in areas of lower [11C]HED retention. A graph comparing subjects with higher/lower regional LV torsion and [11C]HED RI is shown in Figure.These preliminary data suggest that in T1DM changes in sympathetic innervation are associated with early changes in LV torsion. Studies exploring the relationship between sympathetic activation and early diabetic cardiomyopathy in T1DM are ongoing.
- © 2011 by American Heart Association, Inc.