Abstract 18129: Heterogeneity of Sympathetic Nervous Density in the Left Ventricular Wall in Dilated Cardiomyopathy
Introduction: Carbon-11 hydroxyephedrine (HED) is a radiolabelled catecholamine analogue developed for the positron emission tomography (PET) imaging of sympathetic nerve terminals in the heart. We assessed presynaptic sympathetic nervous function in patients with dilated cardiomyopathy (DCM) using PET with HED.
Methods: In 15 patients with DCM in stable conditions and 15 healthy controls, left ventricular (LV) global myocardial blood flow (MBF) was measured using N-13 ammonia PET and then global HED retention index (HED-RI) was determined as myocardial tracer activity between 30-40 minutes divided by the integral of the activity input function. The polar maps of the tracers were divided into 17 segments, and each segmental tracer activity of MBF and HED-RI were normalized to the highest values in each patients. Coefficients of variation (CV) were calculated to assess heterogeneity of MBF and HED-RI densities in the LV wall. Brain natriuretic peptide (BNP) levels were measured in all subjects.
Results: MBF and HED-RI in the LV wall were significantly lower in patients with DCM than in healthy subjects (0.59±0.10 vs 0.78±0.10 mL/min/g, p=0.0003; 6.9±1.9 vs 8.8±2.0 %/min, p=0.02, respectively). The CVs of both MBF and HED-RI were significantly higher in patients with DCM than in healthy subjects (24.7±7.9 vs 17.5±4.1 %, p=0.004; 16.4±5.4 vs 10.3±2.2 %, p=0.0004, respectively). The CVs of HED-RI were significantly correlated with logBNP levels (r=0.65, p=0.0001).
Conclusions: In addition to the global reduction of cardiac sympathetic activity, more heterogeneous sympathetic presynaptic tracer uptake in the LV wall is demonstrated in patients with DCM. The degree of heterogeneity in sympathetic presynaptic activity is significantly related to severity of heart failure.
Author Disclosures: S. Kikuchi: None. S. Kitada: None. K. Yamamoto: None. T. Goto: None. H. Narita: None. A. Iida: None. N. Ohte: None.
- © 2014 by American Heart Association, Inc.