HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Dirk Fritzsche Axel Laczkovics Andreas Liebold Michael Knaut Klaus Matschke Uwe Mehlhorn Dieter Horstkotte Reiner Koerfer Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Fritzsche, D. Articles by Koerfer, R. Search for Related Content PubMed PubMed Citation Articles by Fritzsche, D. Articles by Koerfer, R. Related Collections Valve disease

Ann Thorac Surg 2007;83:542-548
© 2007 The Society of Thoracic Surgeons

---

Original Articles: Cardiovascular

Early Detection of Mechanical Valve Dysfunction Using a New Home Monitoring Device

^a Heart and Diabetes Center North Rhine-Westphalia, Bad Oeynhausen
^b Clinic for Heart Surgery, University of Bochum, Bochum
^c Clinic for Heart Surgery, University of Rostock, Rostock
^d Heart Center Dresden Ltd, Dresden, Germany
^e Department of Cardiology, Rabin Medical Center, Petah Tiqva, Israel
^f Clinic for Heart Surgery, University of Cologne, Cologne, Germany

Accepted for publication July 29, 2006.

^_* Address correspondence to Dr Fritzsche, Heart and Diabetes Center NRW, Georgstr 11, Bad Oeynhausen D-32545, Germany (Email: dfritzsche{at}hdz-nrw.de).

BACKGROUND: After heart valve replacement, patients are at risk of complications that are linked to irregular oral anticoagulation therapy. Depending on the type and position of the valve, the complication rate is 3% to 6% per patient-year. This study presents clinical results of a device enabling early detection of prosthetic dysfunction by frequency measurements.

METHODS: Between November 2003 and March 2006, ThromboCheck devices were handed out to 483 patients after mechanical heart valve replacement from six heart centers. In each case, the devices were calibrated for individual patients early postoperatively. Taking control measurements, the device calculated deviations from calibrated frequency and amplitude ranges using a fast Fourier transform and sent a warning message to the display if any relevant changes occurred. This message was taken as cause to determine morphologic correlations of the disturbance using imaging techniques, for example, echocardiography or fluoroscopy (observation period, 550.7 patient-years; median application period, 15.1 months).

RESULTS: Twenty-five true positive, 1 false positive, and no false negative measurements occurred. Eleven patients (44%) received thrombolytic therapy with streptokinase or recombinant tissue-type plasminogen activator, resulting in normalization of the digital frequency analysis. In 4 patients (16%), international normalized ratio levels were adjusted under temporary heparinization therapy. Normalization of the valve sounds were achieved within 3 to 7 days. Seven patients (28%) required reoperation despite lysis therapy. Sensitivity was 100% during the observation period; specificity was 99.8%.

CONCLUSIONS: Digital frequency analysis represents a reasonable addition to the monitoring of patients after artificial heart valve replacement to detect prosthesis-related complications early on.

This article has been cited by other articles:

				P. M. Kilbridge and D. C. Classen The Informatics Opportunities at the Intersection of Patient Safety and Clinical Informatics J. Am. Med. Inform. Assoc., July 1, 2008; 15(4): 397 - 407. [Abstract] [Full Text] [PDF]

				D. Fritzsche Reply Ann. Thorac. Surg., March 1, 2008; 85(3): 1143 - 1143. [Full Text] [PDF]

				I. M. Hettich, W. B. Eichinger, and R. Lange A New Home Monitoring Device for the Detection of Mechanical Valve Dysfunction Ann. Thorac. Surg., March 1, 2008; 85(3): 1142 - 1143. [Full Text] [PDF]