Related Experiment Video
Updated: Aug 29, 2026
Functional Assessment of the Donor Heart During Ex Situ Perfusion: Insights from Pressure-Volume Loops and Surface Echocardiography
Published on: October 11, 2022
Myocardial hemodynamics, physiology, and perfusion with an axial flow left ventricular assist device in the calf
Egemen Tuzun1, Kazuhiro Eya, Hyun Keun Chee
1Cardiovascular Research Laboratories, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas 77225-0345, USA.
Insights
The Jarvik 2000 left ventricular assist device (LVAD) effectively unloads the heart. This study found no adverse effects on myocardial metabolism or vital organ blood flow in an experimental model.
Area of Science:
- Cardiovascular Science
- Biomedical Engineering
- Medical Devices
Background:
- The Jarvik 2000 axial flow left ventricular assist device (LVAD) is a critical treatment for end-stage heart disease.
- The impact of its continuous flow on myocardial and end-organ perfusion requires experimental investigation.
Purpose of the Study:
- To experimentally evaluate the effects of the Jarvik 2000 LVAD on hemodynamics, cardiac dimensions, myocardial metabolism, and end-organ perfusion.
- To assess the device's performance across a range of operating speeds (8,000-12,000 rpm).
Main Methods:
- Implantation of the Jarvik 2000 pump in eight calves.
- Utilized micromanometry, echocardiography, blood oxygenation, and microsphere studies to measure hemodynamic and perfusion changes.
- Compared data at various pump speeds against baseline (0 rpm).
Main Results:
- The Jarvik 2000 pump successfully unloaded the left ventricle, reducing pressures and dimensions, especially at higher speeds.
- Myocardial oxygen consumption, coronary blood flow, and regional flow distribution remained stable.
- Brain and kidney microcirculation were not adversely affected at any tested pump speed.
- Optimal settings allowed native left ventricular contribution to cardiac output.
Conclusions:
- The Jarvik 2000 LVAD effectively unloads the left ventricle.
- The device does not compromise myocardial metabolism or vital end-organ perfusion.
- It represents a safe and effective option for patients with end-stage heart disease.
Abstract:
The Jarvik 2000 axial flow left ventricular assist device (LVAD) is used clinically as a bridge to transplantation or as destination therapy in end-stage heart disease. The effect of the pump's continuous flow output on myocardial and end-organ blood flow has not been studied experimentally. To address this, the Jarvik 2000 pump was implanted in eight calves and then operated at speeds ranging from 8,000 to 12,000 rpm. Micromanometry, echocardiography, and blood oxygenation measurements were used to assess changes in hemodynamics, cardiac dimensions, and myocardial metabolism, respectively, at different speeds as compared with baseline (pump off, 0 rpm) in this experimental model. Microsphere studies were performed to assess the effects on heart, kidney, and brain perfusion at different speeds. The Jarvik 2000 pump unloaded the left ventricle and reduced end-diastolic pressures and left ventricular dimensions, particularly at higher pump speeds. The ratio of myocardial oxygen consumption to coronary blood flow and the ratio of subendocardial to subepicardial blood flow remained constant. Optimal adjustment of pump speed and volume status allowed opening of the aortic valve and contribution of the native left ventricle to cardiac output, even at the maximum pump speed. Neither brain nor kidney microcirculation was adversely affected at any pump speed. We conclude that the Jarvik 2000 pump adequately unloads the left ventricle without compromising myocardial metabolism or end-organ perfusion.
