cardiac output
The volume of blood pumped by the heart per minute, calculated as heart rate × stroke volume.
Full Definition
Cardiac output represents the total volume of blood ejected by the heart per minute and serves as a fundamental measure of cardiovascular function. Calculated as the product of heart rate and stroke volume, normal cardiac output ranges from 4-8 L/min in healthy adults at rest. Cardiac output is influenced by preload (venous return), afterload (arterial pressure), contractility (intrinsic heart muscle function), and heart rate. Measurement techniques include thermodilution, Fick method, echocardiography, and bioimpedance. Reduced cardiac output characterizes heart failure and cardiogenic shock, while elevated output may occur in sepsis, hyperthyroidism, or high-output states. Cardiac index (cardiac output divided by body surface area) allows for body size comparison between patients.
Usage
Usage note: Include units (L/min) when reporting values; distinguish from cardiac index (L/min/m²).
In Context
- "Thermodilution catheter measurements revealed severely depressed cardiac output of 2.8 L/min." — Hemodynamic assessment report
- "Inotropic support was initiated to augment cardiac output in this cardiogenic shock patient." — Critical care management note