A novel nonlinear afterload for ex vivo heart evaluation: Porcine experimental results

Henry Pigot, Kristian Soltesz, Audrius Paskevicius, Qiuming Liao, Trygve Sjöberg, Stig Steen

Research output: Contribution to journalArticlepeer-review


Background: Existing working heart models for ex vivo functional evaluation of donor hearts often use cardiac afterloads made up of discrete resistive and compliant elements. This approach limits the practicality of independently controlling systolic and diastolic aortic pressure to safely test the heart under multiple loading conditions. We present and investigate a novel afterload concept designed to enable such control. Methods: Six ∼70 kg pig hearts were evaluated in vivo, then ex vivo in left-ventricular working mode using the presented afterload. Both in vivo and ex vivo, the hearts were evaluated at two exertion levels: at rest and following a 20 μg adrenaline bolus, while measuring aortic pressure and flow, left ventricular pressure and volume, and left atrial pressure. Results: The afterload gave aortic pressure waveforms that matched the general shape of the in vivo measurements. A wide range of physiological systolic pressures (93 to 160 mm Hg) and diastolic pressures (73 to 113 mm Hg) were generated by the afterload. Conclusions: With the presented afterload concept, multiple physiological loading conditions could be tested ex vivo, and compared with the corresponding in vivo data. An additional control loop from the set pressure limits to the measured systolic and diastolic aortic pressure is proposed to address discrepancies observed between the set limits and the measured pressures.
Original languageEnglish
Pages (from-to)1794-1803
JournalArtificial Organs
Issue number9
Early online date2022 May 12
Publication statusPublished - 2022 Aug 22

Subject classification (UKÄ)

  • Medical Equipment Engineering
  • Medical Laboratory and Measurements Technologies

Free keywords

  • cardiac afterload
  • ex vivo heart evaluation
  • functional evaluation
  • heart perfusion
  • heart transplantation
  • working heart


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