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Licensed Unlicensed Requires Authentication Published by De Gruyter August 23, 2010

Super-selective electrical stimulation of the left ventricle via a miniaturized magnetized stimulation wire: proof of concept study

Christian Knackstedt, Thomas Schimpf, Andreas Napp, Boerge Wessling, Christine Rothe, Karl Mischke, Uwe Schnakenberg and Patrick Schauerte
From the journal

Abstract

Cardiac resynchronization therapy provides a treatment option for patients with congestive heart failure. Electrodes are usually advanced via the cardiac venous system (CVS). Placement is often hampered by small vessel diameter or tortuosity. The aim of this study was to develop and test a magnetized stimulation wire (MSW) capable of being navigated into small and tortuous CVS branches. Therefore, a conventional guide wire with a permanent magnet and a single stimulation electrode at its tip was coated with iridium oxide at the distal end and insulated except for the very tip (coating thickness: 500 nm, active uncoated area: 10 mm2). The MSW was designed to allow for a remote magnetic steering using a magnetic navigation system (MN) (Stereotaxis™). After in vitro testing of the electrical properties, the MSW was tested in an animal model (n=6 sheep): the MSW was placed in a CVS side branch and navigation characteristics of the MSW were determined. The effective (unipolar) pacing threshold was 4.9±2.4 V (at 2 ms pulse width). The rheobase was 1.89±0.44 V and the chronaxie time was 0.75±0.7 ms. The MSW could be navigated into small CVS branches with reasonable MN properties. This could allow stimulation at CVS sites currently not accessible for conventional stimulation catheters or electrodes.


Corresponding author: Christian Knackstedt, M.D., Institute of Cardiology and Sport Medicine, German Sport University, Am Sportpark, Müngersdorf 6, 50933 Köln, Germany Phone: +49-221-4982-5040 Fax: +49-221-4912-906

Received: 2010-1-18
Accepted: 2010-7-13
Published Online: 2010-08-23
Published Online: 2010-08-23
Published in Print: 2010-10-01

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