pressure-volume loop
A graphical representation of the cardiac cycle showing the relationship between ventricular pressure and volume throughout systole and diastole.
Full Definition
The pressure-volume loop is a fundamental tool in cardiac physiology that plots left ventricular pressure against ventricular volume during one complete cardiac cycle. The loop's shape and area provide information about preload, afterload, contractility, and stroke work. During cardiac anesthesia, understanding PV loops helps interpret hemodynamic changes caused by anesthetic agents, surgical interventions, and pharmacologic manipulations. The end-systolic pressure-volume relationship (ESPVR) and end-diastolic pressure-volume relationship (EDPVR) derived from these loops are load-independent measures of ventricular function.
Usage
Usage note: Hyphenate the compound term; distinguish from individual pressure or volume measurements.
In Context
- "Analysis of the pressure-volume loop revealed decreased contractility following cardioplegic arrest." — Research protocol
- "The rightward shift in the PV loop indicated increased preload after volume administration." — Teaching case