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ASAIO CARDIAC ABSTRACT

DIMINISHED CARDIAC FUNCTION IN CALVES DEVELOPMENT OF A MORE RELEVANT MODEL FOR PHYSIOLOGIC TESTING WITH VAD SUPPORT

Litwak, K N1; Koenig, S C1; Lott, K A1; LOR, L E1; Pantalos, C M1

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The majority of VAD related research and development occurs in calves or sheep with normal cardiac function, primarily allowing for testing of device safety and efficacy. There have been many studies of physiologic consequences of VAD support; however, the studies have either used acute models of diminished cardiac function or chronic studies with normal animals. These methods do not clearly relate to the clinical scenario. An animal with diminished cardiac function would be desirable for chronic testing of pathophysiologic responses to VAD support or development of controller algorithms. Many groups have attempted to produce a large animal with diminished cardiac function, hut due to the inherent technical problems associated with the available methods, these efforts have been unsuccessful. Monensin is widely used in the cattle industry as a coccidiostat and growth promotant. Anecdotal reports suggested that overdoses of Monensin were cardiotoxic. Oral monensin was given to 2 calves (70–80 kg). Within 5 days, there was diminished cardiac function. Systolic blood pressure decreased from 120 to 100 mm Hg. Cardiac output dropped from 12 L/min to 9 L/min. End systolic volume increased from 10 ml to 38 ml, and ejection fraction decreased from 86% to 48%. At necropsy, the heart was mottled with pale streaks and the lumen was distended about 20% greater than normal. While very preliminary, these results suggest that Monensin could provide a simple means of producing diminished cardiac function. Studies of dosage and post-induction care are ongoing.

Copyright © 2004 by the American Society for Artificial Internal Organs