Left atrial V waves following mitral valve replacement are not specific for significant mitral regurgitation

Left atrial or pulmonary capillary wedge pressure V waves are used immediately after mitral valve replacement to evaluate valve competence. However, their correlation with hemodynamically significant regurgitation has not been established. Transesophageal echocardiography (TEE) was used to prospectively examine whether left atrial V waves represented significant mitral regurgitation in 11 patients undergoing mitral valve replacement. Left atrial pressure V waves were measured in the immediate postcardiopulmonary bypass period by direct cannulation of the right superior pulmonary vein and recorded on a paper chart recorder. In each patient, three evaluations of mitral regurgitation by Doppler TEE were made at 15-minute intervals. In 22 of 33 evaluations, left atrial V waves with peak V wave height more than 5 mm Hg above the mean left atrial pressure were present. However, only in 3 of these periods did transesophageal echocardiography show evidence of more than trace mitral regurgitation by pulsed Doppler and color flow mapping. As indicators of mild-to-severe mitral regurgitation diagnosed by TEE, left atrial V waves had a specificity for the three evaluation periods of 40%, 30%, and 40%. Left atrial V waves with peak height greater than 5 mm Hg above mean left atrial pressure frequently appear following mitral valve replacement, but these V waves are nonspecific signs of mitral regurgitation.