The Study
Beta-adrenergic effects on left ventricular filling: influence of aging and exercise training.
This study looked at how older and younger men's hearts fill with blood after giving them a medicine that makes the heart beat harder. It found differences between the groups, but it didn't randomly assign people to groups, so we can't say one thing caused the other — just that they were linked.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
As men age, their hearts change how they fill with blood—less comes in quickly at first, but more comes in later from the upper chamber. Adrenaline still makes the heart fill well, no matter the age.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 538 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Even though older hearts fill slower at first, they still respond just as well to adrenaline as young hearts—meaning the heart’s ability to pump more blood under stress isn’t lost with age.
- 2Older men had much lower early filling rates (P < 0.0001) but higher late filling rates.
- 3Both groups increased filling with adrenaline (P < 0.01), and training didn't improve it.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of applied physiology
Year
1994
Authors
J. Stratton, W. Levy, R. Schwartz, I. Abrass, M. Cerqueira
Related Content
Claims (3)
In healthy young and older men, regular endurance exercise does not improve the heart's ability to fill with blood during stress induced by beta-adrenergic stimulation, even when aerobic fitness improves.
As people age, the heart's ability to increase its rate, pumping strength, and blood output in response to adrenaline diminishes, but the heart's ability to fill with blood during relaxation does not decline at the same rate.
In healthy men, aging changes how the heart fills with blood during relaxation: the early filling phase becomes slower, while the later filling phase becomes stronger, but the heart's overall ability to respond to adrenaline-like stimulation remains unchanged.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.