Ven Contract Imaged by Doppler Color Flow Mapping Predicts the Severity of Eccentric Mitral Regurgitation Better Than Color Jet Area: Chronic Animal Study

Objectives. This study sought to evaluate the relation between the color Doppler-imaged ven contract and the severity of mitral regurgitation (MR) in chronic animal model of MR. Background. The ven contracta, which is defined as the smallest connection between the laminar flow acceleration zone and the turbulent regurgitant jet, has been reported to be clinically useful marker for evaluating the severity of valvular regurgitation. Methods. Six sheep with chronic MR produced by previous operation severing the chordae tendineae were examined. MR jet flows and ven contract widths were imaged using Vingmed 775 scanner with 5-MHz transducer. Image dat were directly transferred in digital format to microcomputer for off-line measurement. MR was quantified as peak and mean regurgitant flow rates, regurgitant stroke volumes and regurgitant fractions determined using mitral and aortic electromagnetic flow probes and flowmeters balanced against each other. Results. Ven contract width correlated well with regurgitant severity determined by electromagnetic flowmeters (r = 0.95, SEE = 0.05 cm, p < 0.0001 for peak regurgitant flow rate; r = 0.85, SEE = 0.08 cm, p < 0.0001 for regurgitant stroke volume; r = 0.90, SEE = 0.07 cm, p < 0.0001 for regurgitant fraction). Conclusions. This study shows that the ven contract width method is useful for predicting the severity of MR. It is simple and conveniently available with high resolution equipment. The quantitative comparisons in the present study lay the foundation for future clinical and research studies using this ven contract technique.