Related Experiment Video
Updated: Jun 15, 2026
Point-of-Care Ultrasound for Peripheral Veno-Arterial Extracorporeal Membrane Oxygenation Without Left Ventricular Venting
Published on: January 17, 2025
Non-invasive flow measurement of a rotary pump ventricular assist device using quantitative contrast echocardiography
Karl Q Schwarz1, Sachin S Parikh, Xucai Chen
1University of Rochester Medical Center, Rochester, New York 14642, USA. karl_schwarz@urmc.rochester.edu
Background:
Many implantable ventricular assist devices (VADs) have no direct measurement of pump output. The aim of this study was to test the hypothesis that quantitative contrast echocardiography can be used to measure VAD output.
Methods:
Contrast-enhanced Doppler velocity-time integral (VTI) was measured in the VAD inlet and outlet cannulae. Doppler flow (Doppler Q=Doppler VTIxcannula area) was compared with measured flow (Q). A total of 130 flow measurements were made (at 6400 and 12,000 rpm).
Results:
Doppler Q in the outflow and inflow cannulae showed an excellent correlation with measured Q (outlet Doppler Q=1.0052 xQ+0.048, R2=0.9865; inlet Doppler Q=1.5043 xQ+0.003, R2=0.9904), but inlet Doppler Q was 50% higher. Correcting for the flow profile of the conical inlet tube yielded excellent correlation (inlet Doppler Q=1.0029 xQ+0.002, R2=0.9904).
Conclusion:
Noninvasive Doppler flow techniques can be used to accurately measure VAD flow, but the flow profile in the cannula needs to be taken into account.
