chronotropic reserve
The heart's ability to increase heart rate appropriately in response to increased metabolic demand or stress.
Full Definition
Chronotropic reserve represents the cardiac capacity to augment heart rate from baseline to age-predicted maximum during physical or pharmacological stress. Normal chronotropic reserve is essential for maintaining adequate cardiac output during exercise and is typically assessed during stress testing. Impaired chronotropic reserve, or chronotropic incompetence, may indicate sinus node dysfunction, medication effects, or underlying cardiovascular disease. The assessment involves calculating the percentage of age-predicted maximum heart rate achieved during stress testing, with values below 85% often considered abnormal.
Usage
Usage note: Distinguish from chronotropic incompetence, which refers to the impairment of this reserve.
In Context
- "The patient demonstrated normal chronotropic reserve, achieving 95% of age-predicted maximum heart rate." — Exercise stress test report
- "Reduced chronotropic reserve may contribute to exercise intolerance in heart failure patients." — Cardiology consultation note