Association between Left Ventricle Sympathetic Innervation and Torsion in Patients with Type 1 Diabetes

Introduction In type 1 diabetes (T1DM), left ventricular (LV) dysfunction often precedes significant coronary artery disease or hypertension. Cardiac autonomic neuropathy (CAN) is associated with an increased prevalence of silent myocardial ischemia and is an independent risk factor for cardiac mortality. Longitudinal studies of CAN subjects have shown 5 year mortality rates between 16-50% (1), particularly in patients with sympathetic CAN. Sympathetic imbalance associated with CAN may critically influence myocardial glucose utilization and contribute to regional ventricular wall motion abnormalities and functional deficits. We have developed the use of positron emission tomography (PET) with [C]metahydroxyephedrine ([C]HED) as a sensitive technique to explore the integrity of the LV sympathetic innervation (Figure 1). We observed that [C]HED tracer retention deficits affected 36-40% of the LV in early-stage T1DM patients, despite normal cardiovascular reflex testing, consistent with sympathetic neuronal dysfunction (2).