Background: During adrenergic stress, the influence of age on left atrial (LA) function is
unknown. We hypothesized that aging decreases LA total emptying fraction (LAEF) during
maximal adrenergic stress. The aim of the study was to determine the influence of aging on LA
function during adrenergic stress in middle aged and older patients.
Methods: We enrolled 167 middle aged and elderly participants, and measured LA and left
ventricular (LV) volumes using a multi-slice three-dimensional cine white blood cardiovascular
magnetic resonance (CMR) technique before and during intravenous dobutamine infused to
achieve 80% of the maximum heart rate response for age. Paired sample t-test was used to
detect differences in LA and LV volumes between baseline and peak dose stage of dobutamine
stress CMR, and multivariable linear regression was used to identify predictors of LA function.
Results: Participants averaged 68 ± 8 years in age, 53% were men, 25% exhibited coronary
artery disease, 35% had diabetes, 9% had a remote history of atrial fibrillation, 90% had
hypertension, and 11% had inducible LV wall motion abnormalities indicative of ischemia
during dobutamine CMR. Increasing age correlated with LA volumes (maximal and minimal)
and inversely correlated with LAEF at rest and after peak adrenergic stress. Age was an independent
predictor of LAEF during adrenergic stress, even after accounting for gender, LV volumes,
and other co-morbidities including inducible ischemia.
Conclusions: Age is associated with a decrease in LA function during adrenergic stress even
after adjusting for co-morbidities associated with cardiovascular disease and LV function.
(Cardiol J 2012; 19, 1: 45–52
