Thorac Cardiovasc Surg 2013; 61 - OP46
DOI: 10.1055/s-0032-1332285

An isolated large animal heart platform for cardiac research and cardiac device testing

M Granegger 1, 2, S Mahr 3, J Horvat 1, P Aigner 1, 2, D Zimpfer 3, H Schima 1, 2, 3, F Moscato 1, 2
  • 1Medizinische Universität Wien, Zentrum für Medizinische Physik und Biomedizinische Technik, Wien, Austria
  • 2Ludwig Boltzmann Cluster für Kardiovaskuläre Forschung, Wien, Austria
  • 3Medizinische Universität Wien, Abteilung für Herzchirurgie, Wien, Austria

Objectives: Several studies were performed using isolated hearts from small animals in the working mode (“ejecting heart”) to investigate e.g. ischemic/reperfusion injuries and drug effects on the myocardium. Only a few groups, however, developed a setup for isolated hearts from large animals capable of reproducing the pathophysiological hemodynamic conditions observed in humans. Aim of this work was to establish a flexible isolated heart setup using pig hearts, which allows pathophysiological studies (e.g. coronary perfusion, oxygen consumption, investigation of drug effects) and the test of cardiovascular devices.

Methods: Pig hearts from the abattoir (n = 20) as well as from animal experiments were used (n = 10). The hearts were arrested, cooled down and prepared for the connection to the isolated heart apparatus. After pressure-controlled coronary reperfusion with warm oxygenated porcine blood the apparatus was switched to “working-mode”, which allowed left ventricular ejection into a Windkessel afterload. This afterload could be modified by an adjustable valve mimicking the arterial resistance; left atrial pressure was controlled by a roller pump. Ventricular contractility could be reversibly reduced by applying halothane with a vaporizer and increased using dobutamine. In 10 hearts a rotary blood pump (RBP) was implanted and the heart/pump hemodynamic interaction investigated.

Results: Human hemodynamic conditions over a wide range were reproduced: In the final setup the cardiac output (CO) generated by the ventricle itself between 0.6 to 9.4L/min at a preload of 15 mmHg and an afterload of 70 mmHg, contractility could be adjusted from a dP/dtmax of 629 to 3625 mmHg/s. Heart rate was in the range between 74 and 170bpm. RBPs were successfully implanted in 10 hearts and the hemodynamics of the assisted circulation reproduced the ones observed in the clinic (mean arterial pressure from 50 to 150 mmHg, mean pump flow and pump flow pulsatility from 0 to 10 L/min at pump speeds from 1800 to 4000rpm).

Conclusions: An isolated heart setup for large animals was developed, which reproduced the human hemodynamics as well as the assisted circulation. By allowing isolated, defined and reversible changes of hemodynamic parameters, this tool does not only provide possibilities for research application but also offers the opportunity to train cardiac surgeons.