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DOI: 10.1055/s-2000-8351
© Georg Thieme Verlag Stuttgart · New York
High-Intensity Transient Signals (HITS) as a Parameter for Optimum Orientation of Mechanical Aortic Valves[*]
Publikationsverlauf
Publikationsdatum:
31. Dezember 2000 (online)
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Background: In previous studies [1] [2], the impact of valve orientation on the hemodynamic performance of mechanical aortic valves has been demonstrated. This study investigates Turbulence (RNS values) and High Intensity Transient Signals (HITS) as a new and objective parameter for hemodynamics in different orientations of Medtronic Hall (MH) and St. Jude Medical (SJM) aortic valves. Methods: A rotation device carrying MH or SJM valves was implanted in 4 pigs. The device allowed valve rotation without reopening the aorta. In different orientations, turbulent shear stresses (RNS values) and HITS were measured. Results: RNS and HITS changed for both valve designs in various orientations, with superior results for the MH in the hemodynamically best orientation. Downstream turbulence (RNS) and HITS varied into the same direction, but a one-to-one correlation was not observed. Conclusions: RNS and HITS vary with respect to valve orientation and design with superior results for the tilting disc valve. Both MH and SJM valves showed lower turbulence and HITS counts in their hemodynamically best orientations. HITS were related to downstream turbulence and the hemodynamic performance of the mechanical aortic valves.
Key words:
HITS - Prosthetic heart valves - Medtronic - SJM
1 Presented at the 3rd Joint Meeting of the German, the Austrian and Swiss Societies for Thoracic and Cardiovascular Surgery, Lucerne, February 9 - 12, 2000
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1 Presented at the 3rd Joint Meeting of the German, the Austrian and Swiss Societies for Thoracic and Cardiovascular Surgery, Lucerne, February 9 - 12, 2000
Prof. Dr. J. Laas
Department of Cardiothoracic Surgery Herz-Kreislauf-Klinik Bevensen
Römstedter Straße 25
29549 Bad Bevensen
Germany
Telefon: 49-5821-821702
Fax: 49-5821-821777
eMail: Prof.Laas@t-online.de