Electrophysiological characterization of GLP-1 effects in vivo and in isolated perfused hearts localized electrical modulation to the atria and conduction system. In isolated sinus nodes, GLP-1 administration shortened the action potential cycle length of pacemaker cells and shifted the site of earliest activation. The effect was independent of HCN blockade. Collectively, these data support a direct effect of GLP-1 on GLP-1 receptors within the heart.

(F ) Illustration showing mapping electrode array placement on the sinus node. (G) High-density maps of activation times were measured across the array (n = 4). Representative maps at baseline (left) and after GLP-1 superfusion (right) are shown. Note the shift in site of earliest activation towards the crista terminalis. (H) Representative high-resolution maps of activation times measured at baseline (left) and in the presence of ivabradine (middle) and ivabradine + GLP-1 (right).

Cardiovascular Research(IF 13.3)

Lubberding AF, Veedfald S, Achter JS, et al. Glucagon-like peptide-1 increases heart rate by a direct action on the sinus node. Cardiovasc Res. 2024;120(12):1427-1441. doi:10.1093/cvr/cvae120