Nuclear Imaging of the Cardiac Sympathetic Nervous System

Abnormalities in the cardiac sympathetic nervous system have been documented in various heart diseases and have been directly implicated in their pathogenesis and disease progression. Noninvasive techniques using single-photon-emitting radiotracers for planar scintigraphy and single-photon emission computed tomography, and positron-emitting tracers for positron emissions tomography, have been used to characterize the cardiac sympathetic nervous system with norepinephrine analogs [123I]meta-iodobenzylguanidine for planar and single-photon emission computed tomography imaging and [11C]meta-hydroxyephedrine for positron emissions tomography. Their usefulness in prognostication and risk stratification for cardiac events has been demonstrated. This review bridges basic and clinical research and focuses on applying an understanding of tracer kinetics and neuronal biology, to aid in the interpretation of nuclear imaging of cardiac sympathetic innervation.