RT Journal Article SR Electronic T1 Cardiac Beta-Adrenergic Receptor Downregulation, Evaluated by Cardiac Positron Emission Tomography, in Chronotropic Incompetence JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP jnumed.120.253419 DO 10.2967/jnumed.120.253419 A1 Toshihiko Goto A1 Shohei Kikuchi A1 Kento Mori A1 Takafumi Nakayama A1 Hidekatsu Fukuta A1 Yoshihiro Seo A1 Hitomi Narita A1 Akihiko Iida A1 Nobuyuki Ohte YR 2020 UL http://jnm.snmjournals.org/content/early/2020/12/18/jnumed.120.253419.abstract AB The mechanism of chronotropic incompetence (CI), which has been associated with autonomic dysfunction, has not been elucidated in patients without heart failure (HF). Methods: Cardiac positron emission tomography using 11C-CGP12177 was performed to investigate the cardiac beta-adrenergic receptor density (β-ARD) in 13 patients with CI without HF and six healthy controls. The maximum number of available specific 11C-CGP12177 binding sites per gram of tissue was calculated in regions of interest using an established graphical method. Results: Peak heart rate was significantly lower in CI patients than in controls (116.9 ± 11.0 vs. 154.8 ± 14.4 beats/min, p < 0.001). β-ARD of the total myocardium was significantly lower in CI patients than in controls (4.3 ± 1.7 vs. 7.0 ± 1.7 pmol/mL, p = 0.005). Conclusion: Beta-adrenergic receptor downregulation was demonstrated in patients with CI without HF. Decreased β-ARD is a common feature in patients with CI, with or without HF.