Dataset Information

Aging reduces left atrial performance during adrenergic stress in middle aged and older patients.

ABSTRACT: 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.

SUBMITTER: Jeevanantham V

PROVIDER: S-EPMC3767009 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Aging reduces left atrial performance during adrenergic stress in middle aged and older patients.

Jeevanantham Vinodh V Chughtai Haroon H Little William C WC Morgan Timothy T Kitzman Dalane W DW Hamilton Craig A CA Hundley W Gregory WG

Cardiology journal 20120101 1

<h4>Background</h4>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.<h4>Methods</h4>We enrolled 167 middle aged and elderly participants, and measured LA and left ventricular (LV) volumes using a multi-slice three-dimensi ...[more]

PMID: 22298167

Similar Datasets

Project description:BackgroundModerate intensity exercise is associated with a decreased incidence of atrial fibrillation. However, extensive training in competitive athletes is associated with an increased atrial fibrillation risk. We evaluated the effects of 24 months of high intensity exercise training on left atrial (LA) mechanical and electric remodeling in sedentary, healthy middle-aged adults.MethodsSixty-one participants (53±5 years) were randomized to 10 months of exercise training followed by 14 months of maintenance exercise or stretching/balance control. Fourteen Masters athletes were added for comparison. Left ventricular (LV) and LA volumes underwent 3D echocardiographic assessment, and signal-averaged electrocardiographs for filtered P-wave duration and atrial late potentials were completed at 0, 10, and 24 months. Extended ambulatory monitoring was performed at 0 and 24 months. Within and between group differences from baseline were compared using mixed-effects model repeated-measures analysis.ResultsFifty-three participants completed the study (25 control, 28 exercise) with 88±11% adherence to assigned exercise sessions. In the exercise group, both LA and LV end diastolic volumes increased proportionately (19% and 17%, respectively) after 10 months of training (peak training load). However, only LA volumes continued to increase with an additional 14 months of exercise training (LA volumes 55%; LV end diastolic volumes 15% at 24 months versus baseline; P<0.0001 for all). The LA:LV end diastolic volumes ratio did not change from baseline to 10 months, but increased 31% from baseline in the Ex group ( P<0.0001) at 24 months, without a change in controls. There were no between group differences in the LA ejection fraction, filtered P-wave duration, atrial late potentials, and premature atrial contraction burden at 24 months and no atrial fibrillation was detected. Compared with Masters athletes, the exercise group demonstrated lower absolute LA and LV volumes, but had a similar LA:LV ratio after 24 months of training.ConclusionsTwenty-four months of high intensity exercise training resulted in LA greater than LV mechanical remodeling with no observed electric remodeling. Together, these data suggest different thresholds for electrophysiological and mechanical changes may exist in response to exercise training, and provide evidence supporting a potential mechanism by which high intensity exercise training leads to atrial fibrillation.Clinical trial registrationURL: https://www.clinicaltrials.gov . Unique identifier: NCT02039154.

Project description:BackgroundLeft atrium (LA) physiology is influenced by changes in left ventricular (LV) performance and load.ObjectivesThe purpose of this study was to define the effect of acute changes in LV loading conditions on LA physiology in subacute myocardial infarction (MI).MethodsMI was percutaneously induced in 19 Yorkshire pigs. One to 2 weeks after MI, 14 pigs underwent acute LV unloading using a percutaneous LV assist device, Impella. The remaining 5 pigs underwent acute LV loading by percutaneous induction of aortic regurgitation. A pressure-volume catheter was inserted into the LA using a percutaneous transseptal approach, and LA pressure-volume loops were continuously monitored. Atrial arrhythmia inducibility was examined by burst-pacing of the right atrium. Nicotinamide adenine dinucleotide phosphate oxidase (NOX) levels and ryanodine receptor phosphorylation were examined in LA tissues to study the potential effect of stretch-dependent oxidative stress.ResultsMI resulted in reduced LV ejection fraction and increased LV end-diastolic pressure with concomitant increase in LA pressure and volumes. Acute LV unloading resulted in a reduction of LV end-diastolic pressure, which led to proportional decreases in mean LA pressure and maximum LA volume. LA pressure-volume loops exhibited a pump flow-dependent, left-downward shift. This was associated with reduced LA passive stiffness, suggesting the alleviation of the LA stretch that was present after MI. Prior to acute unloading of the LV, 71% of the pigs were arrhythmia-inducible; LV unloading reduced this to 29% (p = 0.02). Time to spontaneous termination of atrial arrhythmias was decreased from median 55 s (range 5 to 300 s) to 3 s (range 0 to 59 s). In contrast, acute LV loading with aortic regurgitation increased LA pressure without a significant effect on arrhythmogenicity. Molecular analysis of LA tissue revealed that NOX2 expression was increased after MI, whereas acute LV unloading reduced NOX2 levels and diminished ryanodine receptor phosphorylation.ConclusionsAcute LV unloading relieves LA stretch and reduces atrial arrhythmogenicity in subacute MI.

Project description:Background:Self-rated Health (SRH) is regarded as a simple and valid measure of a person's health status, given its association to adverse health outcomes, including low physical performance in older populations. However, studies investigating these associations in low- and middle-income settings are scarce, especially for middle-aged populations. Understanding the validity of SRH in relation to objective health measures in low-income populations could assist in decision making about health policy and strategies, especially in under-resourced settings. Objective:Assess the relationship between SRH and physical performance measures in middle-aged and older women in a low-income setting of Brazil. Methods:This is a cross-sectional study of 571 middle-aged (40-59 years old) and older (60-80 years old) women living in Parnamirim and Santa Cruz in the Northeast region of Brazil. Participants reported their health status and were allocated to the "SRH good" or "SRH poor" groups. The physical performance evaluation included: handgrip strength, one-legged balance with eyes open and closed and chair stand test. The relationship between SRH and physical performance for middle-aged and older women was assessed by quantile regression (modeling medians) adjusted for potential confounders (age, socioeconomic variables, body mass index, menopause status, age at first birth, parity, chronic conditions and physical activity). Results:Middle-aged women from the "SRH good" group presented better physical performance with 1.75 kgf stronger handgrip strength (95% CI [0.47-3.02]; p = 0.004), 1.31 s longer balance with eyes closed ([0.00-2.61]; p = 0.030), and they were 0.56 s faster in the chair stand test ([0.18-0.94]; p = 0.009) than those who reported "SRH poor". No association was found for balance with eyes open. For older women, there was no evidence of associations between physical performance and SRH. Conclusion:This study showed that SRH is significantly associated with objective measures of physical performance in a sample of low-income middle-aged women. SRH can be an important tool to indicate the need for further evaluation of physical performance among middle-aged women and can be particularly useful for low-income communities.

Dataset Information

Aging reduces left atrial performance during adrenergic stress in middle aged and older patients.

Publications

Aging reduces left atrial performance during adrenergic stress in middle aged and older patients.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets