Evidence for pre- to post synaptic mismatch of the cardiac sympathetic nervous system in ischemic congestive heart failure

Abstract

Pre- and postsynaptic cardiac sympathetic function is altered in ischemic congestive heart failure (CHF). Whether there is a presynaptic-to-postsynaptic mismatch or whether mismatch is related to adverse cardiac events is unknown. Methods: In 13 patients with ischemic CHF and 25 aged-matched healthy volunteers, presynaptic function was measured by PET of 11C-meta-hydroxyephedrine (11C-mHED), a norepinephrine (NE) an-alog. Postsynaptic function, b-adrenergic receptor (BAR) density (B9max), was measured by imaging 11C-CGP12177. Myocardial blood flow (MBF) was measured by imaging 15O-water. Each heart was analyzed both globally and regionally, excluding in-farcted regions, and a mismatch score, defined as the ratio of B9max to NE uptake (PSnt), was used to indicate mismatch of post- and presynaptic function. Results: Global and regional MBF was not different between CHF and healthy subjects. Th