ISSN : 1301-5680
e-ISSN : 2149-8156
Turkish Journal of Thoracic and Cardiovascular Surgery     
The Effect of Left Ventricle Unloading By The Jarvik 2000 Assist Device on Coronary Blood Flow
Egemen Tüzün, Kanber Öcal Karabay, Jeff Conger, Howard Frazier, Kamuran Kadıpaşaoğlu
Cardiovascular Surgery Labs, Texas Heart Institute, Houston/TX, USA
Background: The purpose of this study was to evaluate the effects of left ventricle unloading by the Jarvik 2000 axial-flow pump on coronary blood flow.

Methods: The Jarvik 2000 pump was implanted in 10 calves using partial cardiopulmonary bypass. Left ventricular (LV) hemodynamics, coronary blood flow (CBF), and myocardial oxygen consumption (MVO2) were measured when the pump was operating at 8,000, 10,000 and 12,000 rpm, and the results were compared with the baseline (pump off, 0 rpm) values. Echocardiography was performed at increasing speeds to evaluate left and right ventricular dimensions and aortic valve opening.

Results: No surgical or device-related complications occurred. The Jarvik 2000 significantly increased the mean and diastolic aortic pressures and resulted in narrowed pulse pressure at speeds above 10,000 rpm (p<0.05). Left ventricular end-systolic and end-diastolic pressures, pulmonary capillary wedge pressure, and LV dimensions gradually decreased at higher pump speeds. Although coronary blood flow and myocardial oxygen consumption decreased at increasing pump speeds (p<0.05), the ratio of CBF to MVO2 remained between 0.18 and 0.20 in all calves throughout the study. Right heart pressures were not affected by increases in pump speeds and remained close to the baseline values.

Conclusion: We conclude that left ventricle unloading with Jarvik 2000 pump does not compromise LV functions and affect CBF/MVO2 ratio.

Keywords : Blood flow velocity; blood pressure; coronary circulation; echocardiography; heart-assist devices; heart failure, congestive; myocardium; oxygen consumption; prosthesis implantation; vascular resistance; ventricular function, left
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