VENA CONTRACTS IMAGED BY DOPPLER COLOR-FLOW MAPPING PREDICTS THE SEVERITY OF ECCENTRIC MITRAL REGURGITATION BETTER THAN COLOR JET AREA - A CHRONIC ANIMAL STUDY

Objectives. This study sought to evaluate the relation between the col or Doppler-imaged vena contracta and the severity of mitral regurgitat ion (MR) in a chronic animal model of MR. Background. The vena contrac ta, which is defined as the smallest connection between the laminar fl ow acceleration zone and the turbulent regurgitant jet, has been repor ted to be a clinically useful marker for evaluating the severity of va lvular regurgitation, Methods. Six sheep with chronic MR produced by p revious operation severing the chordae tendineae were examined. MR jet hows and vena contracta widths were imaged using a Vingmed 775 scanne r with a 5-MHz transducer. Image data were directly transferred in dig ital format to a microcomputer for off-line measurement. MR was quanti fied as peak and mean regurgitant how rates, regurgitant stroke volume s and regurgitant fractions determined using mitral and aortic electro magnetic how probes and flowmeters balanced against each other. Result s. Vena contracta width correlated well,vith regurgitant severity dete rmined by electromagnetic flowmeters (r = 0.95, SEE = 0.05 cm, p < 0.0 001 for peak regurgitant flow rate; r = 0.85, SEE = 0.08 cm, p < 0.000 1 for regurgitant stroke volume; r = 0.90, SEE = 0.07 cm, p < 0.0001 f or regurgitant fraction). Conclusions. This study shows that the vena contracta 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 f or future clinical and research studies using this vena contracta tech nique. (C) 1997 by the American College of Cardiology.