What does the left atrial V wave signify during balloon commissurotomy of mitral stenosis?

Left atrial v-wave amplitude has been associated with the presence and seve rity of chronic mitral regurgitation (MR) but it has not been evaluated for the detection of acute MR. We evaluated the left atrial v-wave amplitude o f 205 consecutive patients with mitral stenosis immediately before and afte r stepwise, incremental balloon mitral commissurotomy to determine predicto rs of large v waves at baseline and an increase in v-wave amplitude after b alloon commissurotomy. The sensitivity and specificity of an increase in v- wave amplitude for detecting worsening and severe MR were determined. A lar ge v wave was present in 44% of patients before balloon commissurotomy and was predicted by age, mean left atrial pressure, mean transmitral gradient, mean pulmonary artery pressure, and angiographic severity of MR. There was a strong inverse correlation between v-wave amplitude and calculated left atrial compliance (r = -0.92). An increase in v-wave amplitude after balloo n commissurotomy was associated with arl increasing probability of worsenin g or severe MR. This indicator had a sensitivity, specificity, and positive and negative predictive values of 35%, 91%, 64%, 75%, respectively, for de tecting any increase in MR. For the detection of severe MR, the sensitivity was 79%, specificity 89%, positive predictive value 42%, and negative pred ictive value 98%. Thus, left atrial v-wave amplitude reflects left atrial c ompliance and severity of mitral stenosis before balloon commissurotomy. An increase in v-wave amplitude is an insensitive but very specific indicator of worsening or severe MR during stepwise, incremental balloon mitral comm issurotomy. (C) 1998 by Excerpta Medica, Inc.