Evaluation of a fluid-controlled artificial heart.

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Medical Devices

Background:

• Pneumatic drive biventricular cardiac prostheses are critical for end-stage heart failure.
• The Zurich artificial heart (AH) utilizes a silicone rubber membrane and tilting disc valves for biventricular support.
• Monitoring membrane position is essential for preventing device malfunction during the cardiac cycle.

Purpose of the Study:

• To evaluate the short-term performance and biocompatibility of the Zurich artificial heart (AH) in a canine model.
• To assess hemodynamic parameters and physiological responses following AH implantation.
• To identify biological challenges associated with prolonged artificial heart pumping.

Main Methods:

• Implantation of the Zurich AH in 25 dogs (23-50 kg).
• Monitoring of membrane position, aortic pressure, and atrial pressures.
• Assessment of animal survival, spontaneous respiration, plasma hemoglobin, and platelet counts.
• Evaluation of transplant function after AH explantation in select cases.

Main Results:

• The Zurich AH demonstrated satisfactory performance in 5 animals for over 24 hours.
• Hemodynamic parameters including aortic pressure and atrial pressures remained within normal ranges.
• Animals were awake and breathed spontaneously after 24 hours, with elevated plasma hemoglobin and decreased platelet counts.
• While transplants showed adequate function, no long-term survivors were achieved due to biological complications.

Conclusions:

• The Zurich AH can provide adequate short-term hemodynamic support in a canine model.
• Prolonged use of the artificial heart presents significant biological challenges, including hemostasis, sepsis, and organ dysfunction.
• Further research is needed to overcome these biological hurdles for successful long-term application of biventricular assist devices.