Age-associated electrophysiological changes of rat atrial muscle / 中华老年医学杂志

ABSTRACT

Objective To investigate the age-associated changes of electrophysiological properties of atrial muscle and the relationship between these changes and atrial fibrillation (AF). Methods According to their ages forty Wistar rats were divided into 4 age groups young group, adult group, middle-aged group and old group (n=10 each group ). Hearts were isolated and perfused by Langendorff. MAP (monophasic action potential) of atrial muscle was recorded. MAPD (duration of MAP) and ERP (effective refractory period) at 400 ms of the stimulation cycle length, and MAPD at other different stimulation cycle lengths were measured in each group. Results At the stimulation cycle length of 400 ms, MAPD_(90) of right atrial muscle prolonged gradually from young group to old group (P