Aging reduces left atrial performance during adrenergic stress in middle aged and older patients.
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.
Department of Internal Medicine (Cardiology Section), Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1045, USA.
Vinodh
V
Jeevanantham
Haroon
H
Chughtai
William C
WC
Little
Timothy
T
Morgan
Dalane W
DW
Kitzman
Craig A
CA
Hamilton
W Gregory
WG
Hundley
D058665:Adrenergic beta-1 Receptor Agonists / Q000008:administration & dosage; D000367:Age Factors; D000368:Aged; D000375:Aging; D016279:Atrial Function, Left; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000503:physiopathology*; D016009:Chi-Square Distribution; D004280:Dobutamine / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D016014:Linear Models; D008137:Longitudinal Studies; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009657:North Carolina; D015588:Observer Variation; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013312:Stress, Physiological; D016277:Ventricular Function, Left
D058665:Adrenergic beta-1 Receptor Agonists; D004280:Dobutamine