cardiac output reserve
The ratio of peak exercise cardiac output to resting cardiac output, reflecting the heart's ability to increase total blood flow during stress.
Full Definition
Cardiac output reserve represents the heart's capacity to augment total blood flow in response to physiological or pharmacological stress. It is calculated as the ratio of peak stress cardiac output to resting cardiac output, with normal values typically ranging from 3-5 in healthy individuals. This parameter reflects the integrated function of heart rate response, stroke volume reserve, and overall cardiovascular fitness. Reduced cardiac output reserve may indicate systolic or diastolic dysfunction, chronotropic incompetence, or vascular limitations. Assessment can be performed using exercise testing with direct Fick method, thermodilution, or non-invasive techniques such as stress echocardiography with Doppler-derived stroke volume measurements.
Usage
Usage note: Express as ratio or percentage increase; specify measurement technique when reporting.
In Context
- "Cardiac output reserve was markedly reduced at 2.1, indicating significant functional impairment." — Exercise hemodynamic assessment
- "The patient demonstrated normal cardiac output reserve despite mild resting systolic dysfunction." — Stress testing evaluation