Related Experiment Video
Updated: Apr 23, 2026
Use of Two Intracorporeal Ventricular Assist Devices As a Total Artificial Heart
Published on: May 11, 2018
Comparison of Intraoperative Doppler Flow Measurements and Algorithmic Flow Estimations in Patients Undergoing
Gaik Nersesian1,2, Anna Stegmann1,2, Daniel Lewin1
1Department of Cardiothoracic and Vascular Surgery, Deutsches Herzzentrum der Charité (DHZC), Berlin, Germany.
Introduction:
Left ventricular assist devices (LVAD) have become an established therapy for end-stage heart failure over the last three decades. In currently available devices, the blood flow is estimated using a power consumption algorithm. In this study, intraoperative direct LVAD flow measurement with an ultrasonic flow probe was analyzed.
Methods:
As part of our routine evaluation of optimal LVAD flow, intraoperative direct flow measurement at the outflow graft was performed using a 14-mm ultrasonic flow probe. Direct LVAD flow measurements were performed at different speed levels: 4400 rpm, 4800 rpm, 5200 rpm, and the optimal flow setting before chest closure. In twenty consecutive patients who underwent a durable LVAD implantation via median sternotomy in our institution between January and April 2025, direct flow measurement was compared with the estimated flow provided by the device.
Results:
Median age was 63 [60;68] years, 17 (85%) were male, 8 (40%) had a history of acute myocardial infarction. Temporary mechanical circulatory support with a microaxial flow pump was necessary in 8 (40%) patients prior to durable LVAD implantation. Destination therapy was indicated in 12 (60%) cases. Mean flows at 4400 rpm were 2.9 ± 0.3 and 3.4 ± 0.4 L/min calculated by the pump and measured by the probe, respectively. Mean difference between the measurements was 0.56 L/min (95% CI [0.40, 0.70], p < 0.001). Mean flows at 4800 rpm were 3.5 ± 0.3 and 4.1 ± 0.5 L/min, respectively. Mean difference between the measurements was 0.55 L/min (95% CI [0.33, 0.77], p < 0.001). Mean flows at 5200 rpm were 4.2 ± 0.3 and 4.7 ± 0.5 L/min, respectively. Mean difference between the measurements was 0.53 L/min (95% CI [0.40, 0.70], p = 0.001). Mean optimal speed for patients was 5400 rpm, mean difference between the measurements was 0.49 L/min (95% CI [0.23, 0.74], p = 0.001).
Conclusion:
LVAD flow measured with an ultrasonic flow probe shows significantly higher results (approximately +0.5 L/min) compared to the flow estimated by the device. The difference remains constant at different LVAD speed modes. Intraoperative flow measurement employing an ultrasonic flow probe is a valuable tool for hemodynamic evaluation during implantation of a durable LVAD.
