DruckVolumenLoop

DruckVolumenLoop, known in English as the pressure-volume loop (PV loop), is a graphical representation of left ventricular function. It plots instantaneous left ventricular pressure against left ventricular volume throughout the cardiac cycle, producing a loop that reflects systolic and diastolic phases. The measurement is typically obtained with an invasive catheter setup, combining a micromanometer for pressure with a conductance or admittance sensor for volume. The loop comprises four phases: isovolumetric contraction, rapid ejection, isovolumetric relaxation, and rapid filling.

Interpretation of the PV loop provides insight into preload, afterload, contractility, and diastolic function. The area inside the loop equals stroke work; the slope of the end-systolic pressure-volume relation (ESPVR) is a measure of contractility, while the end-diastolic pressure-volume relation (EDPVR) reflects compliance. The stroke volume is the difference between end-diastolic and end-systolic volumes. The PV loop helps distinguish effects of preload (changes in filling) and afterload (arterial pressure) from changes in contractility, making it more informative than ejection fraction alone.

Methods and limitations: The most common acquisition uses a conductance catheter; volumes require calibration and correction for parallel conductance. Results depend on catheter position and body size; the measurement is invasive and typically confined to research, operating rooms, or advanced hemodynamic monitoring. Noninvasive estimates exist but rely on modeling and have limitations.

Historical and scope: The PV loop concept dates to the mid-20th century and has become a standard tool in physiology and cardiology for understanding ventricular mechanics. In practice, its use is primarily in research, inotropic testing, and specialized intraoperative monitoring. The term DruckVolumenLoop corresponds to the German-language expression for this concept.