Thorac Cardiovasc Surg 2006; 54 - PP_39
DOI: 10.1055/s-2006-925821

In vitro study of jet volumes and regurgitant flow rates for quantitative assessment of mitral valve regurgitation

R De Simone 1, G Glombitza 2, J Ambrus 3, YR Woo 3, I Wolf 2, HP Meinzer 2, S Hagl 1
  • 1Universität Heidelberg, Herzchirurgie, Heidelberg, Germany
  • 2DKFZ, Medical and Biological Informatics, Heidelberg, Germany
  • 3St. Jude Medical, Minnesota, United States of America

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.