A method for the measurement of left ventricular overload for aortic valve insufficiency.
J Biomech
; 42(12): 1935-40, 2009 Aug 25.
Article
em En
| MEDLINE
| ID: mdl-19524244
ABSTRACT
BACKGROUND:
The degree of left ventricular overload in patients with aortic valve insufficiency (AI) plays an important role in determining the need and timing of surgical intervention. Because hemodynamic evaluation of AI may potentially predict the effects of an insufficient valve on the ventricle before they occur, it would be useful to guide valve surgery with such a diagnostic tool. The purpose of this study was to test the performance of a new hemodynamic index based on mechanical energy loss for the measurement of the effects of insufficiency on ventricular workload. METHODS ANDRESULTS:
An intact and subsequently perforated aortic bioprosthesis was tested within an in vitro model of the left heart, varying cardiac output, diastolic aortic pressure, and the size of perforation. Regurgitant orifice area (ROA), regurgitant volume (RV), regurgitant fraction (RF), and energy loss index (ELI) were measured for each experimental condition and plotted against the increase in workload per unit volume net forward flow (DeltaWPV) due to perforation. ROA, RV, and RF showed good correlations with DeltaWPV, but the relationship between these variables and DeltaWPV became ambiguous as their magnitudes increased. ELI had a near perfect linear relationship with DeltaWPV (slope=1.00, r(2)=0.98) independent of the experimental condition.CONCLUSIONS:
RV, RF, and ROA do not by themselves fully describe the increase in difficulty the ventricle has in moving the blood across an insufficient valve. ELI, in contrast, was found to be a very good measure of the decrease in pump efficiency due to aortic valve insufficiency.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Insuficiência da Valva Aórtica
/
Ventrículos do Coração
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
J Biomech
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Estados Unidos
País de publicação:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
/
US
/
USA