Altered adrenergic response in myocytes bordering a chronic myocardial infarction underlies in vivo triggered activity and repolarization instability.

ABSTRACT:

Key points

Ventricular arrhythmias are a major complication after myocardial infarction (MI), associated with sympathetic activation. The structurally heterogeneous peri-infarct zone is a known substrate, but the functional role of the myocytes is less well known. Recordings of monophasic action potentials in vivo reveal that the peri-infarct zone is a source of delayed afterdepolarizations (DADs) and has a high beat-to-beat variability of repolarization (BVR) during adrenergic stimulation (isoproterenol, ISO). Myocytes isolated from the peri-infarct region have more DADs and spontaneous action potentials, with spontaneous Ca²⁺ release, under ISO. These myocytes also have reduced repolarization reserve and increased BVR. Other properties of post-MI remodelling are presen

SUBMITTER: Dries E 

PROVIDER: S-EPMC7496440 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature