Predictive value of prominent pulmonary arterial wedge V waves in assessing the presence and severity of mitral regurgitation.

Indwelling pulmonary arterial catheters are often used to monitor and to guide therapy in critically ill patients. The magnitude of the V wave recorded from the pulmonary arterial wedge (PAW) position is sometimes used to assess the presence and severity of mitral regurgitation (MR). The present study was performed to assess the relation (or lack thereof) between a "prominent" PAW V wave and qualitative and quantitative estimates of MR. In 903 subjects (445 men and 458 women, aged 49 +/- 13 [mean +/- SD] years) referred for cardiac catheterization, an oximetrically confirmed PAW pressure was recorded with a large-lumen stiff catheter, and a left ventriculogram was recorded. In 646 of these subjects (328 men and 318 women, aged 50 +/- 13 years), forward cardiac output was measured by the Fick principle, and a regurgitant fraction was calculated. Prominent PAW V waves--as defined in several ways--were insensitive and had poor positive predictive value in identifying moderate or severe MR. At the same time, the absence of prominent PAW V waves was relatively specific for the absence of moderate or severe MR, and the negative predictive value of small V waves was very good. Thus, the prominence of a PAW V wave cannot be used to assess the presence or severity of MR.