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Titolo:
High-frequency pressure fluctuations measured in heart valve patients
Autore:
Paulsen, PK; Jensen, BK; Hasenkam, JM; Nygaard, H;
Indirizzi:
Aarhus Univ Hosp, Skejby Sygehus, Dept Cardiothorac & Vasc Surg, DK-8200 Aarhus N, Denmark Aarhus Univ Hosp Aarhus Denmark N & Vasc Surg, DK-8200 Aarhus N, Denmark
Titolo Testata:
JOURNAL OF HEART VALVE DISEASE
fascicolo: 5, volume: 8, anno: 1999,
pagine: 482 - 486
SICI:
0966-8519(199909)8:5<482:HPFMIH>2.0.ZU;2-B
Fonte:
ISI
Lingua:
ENG
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Citazioni:
8
Recensione:
Indirizzi per estratti:
Indirizzo: Nygaard, H Aarhus Univ Hosp, Skejby Sygehus, Dept Cardiothorac & Vasc Surg, Brendstrupgaardsvej, DK-8200 Aarhus N, Denmark Aarhus Univ Hosp Brendstrupgaardsvej Aarhus Denmark N Denmark
Citazione:
P.K. Paulsen et al., "High-frequency pressure fluctuations measured in heart valve patients", J HEART V D, 8(5), 1999, pp. 482-486

Abstract

Background and nim of the study: Due to the risk of thromboembolic complications, mechanical heart valve patients require life-long anticoagulant therapy, in contrast to bioprosthetic valves. The reason for this is still notfully understood. In vitro studies have demonstrated the presence of cavitation bubbles in the vicinity of mechanical heart valves, but not of bioprosthetic valves. When cavitation bubbles collapse, they release a significant amount of energy, which may damage the formed elements of the blood. A correlation between the presence of cavitation bubbles and high-frequency pressure oscillations has been established in vitro. Thus, the aim of this study was to measure and quantify high-frequency pressure oscillations in patients with normal, bioprosthetic or mechanical aortic valves. Methods: Measurements were performed in six patients with normal aortic valves after coronary bypass surgery, in five patients fitted with a Carpentier-Edwards pericardial bioprosthesis, and in nine patients fitted with a St. Jude Medical or CarboMedics aortic valve. High-frequency pressure fluctuations were measured intraoperatively using a hydrophone placed near the aortic annulus. The root mean square (RMS) value of the high-frequency pressure signals were calculated in the frequency range 35-150 kHz. Results: High-frequency pressure fluctuations, with intensities above the noise floor, were registered only in the vicinity of mechanical heart valveprostheses, and not in the vicinity of normal or bioprosthetic valves. Themean value of RMS pressure fluctuations was 0.5 Pa for normal aortic valves, 0.8 Pa for bioprosthetic valves, and 67 Pa for mechanical valves. Conclusions: This study is the first to show the presence of high-frequency pressure fluctuations in patients with mechanical valves.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 29/09/20 alle ore 23:55:27