Subscribe to RSS
DOI: 10.1055/s-2006-925821
In vitro study of jet volumes and regurgitant flow rates for quantitative assessment of mitral valve regurgitation
Objectives: Quantitative assessment of mitral regurgitation (MR) continues to be a challenge for clinicians. We performed 2 in vitro studies for assessing the relationship between regurgitant jet volumes by 3D-Color Doppler and the actual regurgitation flow rate.
Methods: Study 1. 64 measurements were obtained by centrifugal pump system connected to membranes with different orifices. Jet volumes were measured by 3D-Doppler at different flow rates and pressure gradients. Eccentric regurgitation jets were obtained by deviating the flow along a convex surface. Measurements of symmetrical and eccentric jets were obtained at the different conditions.
Study 2. Regurgitation flow was measured in a pulse duplicator for testing prosthetic valves, including a pneumatic pump, an atrial and ventricular chamber, an allotment hosting the valves, 2 catheters for pressure measurements and 2 flowmeters. An echocardiographic probe was placed into the atrial chamber (Figure 1). Different degrees of MR were obtained by using biological valves with 7 circular and 7 linear defects, at different ejection rates and pressure gradients
Fig. 1. Pulse Duplicator
Results: In both series (symmetrical and eccentric jets) a significant correlation between jet volumes and flow rate was found. No significant differences were found between the flow rate of symmetrical and eccentric jets. A significant correlation between jet volumes and regurgitation flow rate was found at different flow and pressure conditions and with different regurgitant orifices (Table 1).
Steady Flow – Symmetrical jets Flow Rate vs. Jet Volume |
r=0.96 |
y=1.7+10.2x |
SEE=1.93 |
p<0.001 |
Steady Flow – Eccentric jets Flow Rate vs. Jet Volume |
r=0.96 |
y=1.9+9.9x |
SEE=1.95 |
p<0.001 |
Pulsatile Flow – Regurg. Flow Rate vs. Jet Volume |
r=0.98 |
y=2.8+1.1x |
SEE=2.3 |
p<0.001 |
Conclusion: The results demonstrated that regurgitant jet volumes significantly correlated to the actual regurgitation flow rate, independent of regurgitant orifice shapes, of pressure gradients and of geometrical jet eccentricity.