Related Experiment Video
Updated: Nov 15, 2025

Using Near-Infrared Spectroscopy Wearable Devices to Identify Central Versus Peripheral Limitations During Exercise
Published on: December 19, 2024
Chronotropic Incompetence Limits Aerobic Exercise Capacity in Patients Taking Beta-Blockers: Real-Life Observation of
Krzysztof Smarz1, Maciej Tysarowski1,2, Beata Zaborska1
1Department of Cardiology, Centre of Postgraduate Medical Education, Grochowski Hospital, 04-073 Warsaw, Poland.
Background:
Chronotropic incompetence in patients taking beta-blockers is associated with poor prognosis; however, its impact on exercise capacity (EC) remains unclear.
Methods:
We analyzed data from consecutive patients taking beta-blockers referred for cardiopulmonary exercise testing to assess EC. Chronotropic incompetence was defined as chronotropic index (CI) ≤ 62%.
Results:
Among 140 patients all taking beta-blockers (age 61 ± 9.7 years; 73% males), 64% with heart failure, chronotropic incompetence was present in 80.7%. EC assessed as peak oxygen uptake was lower in the group with chronotropic incompetence, 18.3 ± 5.7 vs. 24.0 ± 5.3 mL/kg/min, p < 0.001. EC correlated positively with CI (β = 0.14, p < 0.001) and male gender (β = 5.12, p < 0.001), and negatively with age (β = -0.17, p < 0.001) and presence of heart failure (β = -3.35, p < 0.001). Beta-blocker dose was not associated with EC. Partial correlation attributable to CI accounted for more than one-third of the variance in EC explained by the model (adjusted R2 = 59.8%).
Conclusions:
In patients taking beta-blockers, presence of chronotropic incompetence was associated with lower EC, regardless of the beta-blocker dose. CI accounted for more than one-third of EC variance explained by our model.
More Related Videos
04:20Integration of Brain Tissue Saturation Monitoring in Cardiopulmonary Exercise Testing in Patients with Heart Failure
Published on: October 1, 2019
08:35Oxygenation-sensitive Cardiac MRI with Vasoactive Breathing Maneuvers for the Non-invasive Assessment of Coronary Microvascular Dysfunction
Published on: August 17, 2022
Related Concept Videos
Heart Failure Drugs: β-Blockers
Adrenergic Antagonists: Pharmacological Actions of β-Receptor Blockers
Antihypertensive Drugs: Types of β-Blockers
Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers
Decreased pulse rate
There are specific risk factors that can elevate the likelihood of developing bradycardia. Advanced age is a significant factor, with...
Adrenergic Antagonists: ɑ and β-Receptor Blockers