Document Detail

Hemodynamics of St. Jude Medical prostheses in the small aortic root: in vivo studies using dobutamine Doppler echocardiography.
MedLine Citation:
PMID:  9130118     Owner:  NLM     Status:  MEDLINE    
BACKGROUND AND AIMS OF THE STUDY: The well known correlation between prosthetic valve orifice area and transvalvular pressure drop has raised concerns about the presence of significant residual gradients when only a small-sized prosthesis can be implanted, particularly in patients with a large body surface area. The aim of this study was to study the hemodynamic performance of small-size St. Jude Medical aortic prostheses using dobutamine echocardiography. METHODS: Fifteen patients (14 females, one male, of mean age 67 years) who had undergone aortic valve replacement with size 19 mm St. Jude Medical prostheses at a mean of 19 +/- 8 (SD) months previously were studied. Dobutamine infusion was started at a rate of 5 micrograms/kg/min and increased to 10 and subsequently to 20 micrograms/kg/min at 15-min intervals. Pulsed and continuous-wave Doppler studies were performed at rest and at the end of each stage. Effective orifice area (EOA) and mean gradient across each prosthesis were calculated, and cardiac output (CO) was determined by Doppler measurement of flow in the left ventricular outflow tract. RESULTS: Dobutamine-stress increased heart rate and cardiac output by 57% and 86% respectively (both p < 0.0005), and mean transvalvular gradient increased from 22.0 +/- 4.9 mmHg at rest to 41.9 +/- 9 mmHg at maximum stress (p < 0.0001). Regression modeling analyses demonstrated that maximum stress gradient was independent of all variables except resting gradient (p = 0.0068). Body surface areas had no effect on the changes in cardiac output, effective orifice area or transprosthetic gradient at maximum stress. CONCLUSIONS: These data demonstrate that the size 19 mm St. Jude Medical prosthesis exhibits favorable hemodynamic performance. Transvalvular gradients remained within a clinically acceptable range, both at rest and under stress conditions. Moreover, in the patient population studied, overall hemodynamic performance indicates that with St. Jude Medical aortic valves, patient-prosthesis mismatch is unlikely to be a problem of clinical importance.
I Kadir; M B Izzat; I Birdi; P Wilde; B Reeves; A J Bryan; G D Angelini
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Publication Detail:
Type:  Clinical Trial; Journal Article    
Journal Detail:
Title:  The Journal of heart valve disease     Volume:  6     ISSN:  0966-8519     ISO Abbreviation:  J. Heart Valve Dis.     Publication Date:  1997 Mar 
Date Detail:
Created Date:  1997-06-27     Completed Date:  1997-06-27     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  9312096     Medline TA:  J Heart Valve Dis     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  123-9     Citation Subset:  IM    
Bristol Heart Institute, UK.
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MeSH Terms
Aged, 80 and over
Aortic Valve Stenosis / surgery*,  ultrasonography
Cardiotonic Agents / administration & dosage,  diagnostic use*
Dobutamine / administration & dosage,  diagnostic use*
Echocardiography, Doppler / methods
Evaluation Studies as Topic
Exercise Test
Heart Valve Prosthesis / instrumentation*,  methods
Hemodynamics / physiology
Infusions, Intravenous
Middle Aged
Postoperative Complications / diagnosis*,  physiopathology
Regression Analysis
Sensitivity and Specificity
Ventricular Function, Left
Reg. No./Substance:
0/Cardiotonic Agents; 34368-04-2/Dobutamine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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