Relationship between pulmonary capillary wedge V wave and transmitral and pulmonary venous flow velocity patterns in various heart diseases.

Background: A large V wave in a pulmonary capillary wedge pressure (PCWP) tracing is characteristic of mitral regurgitation. However, the V wave is often increased in patients without or with no significant mitral regurgitation.
Methods and Results: The V wave was in the PCWP tracing investigated in 65 patients using transmitral flow (TMF) and pulmonary venous flow (PVF) velocity patterns obtained by transesophageal pulsed Doppler echocardiography. A large V wave was defined if the peak V wave minus the mean PCWP (V-mPCWP) was greater than 7 mmHg. Three study groups were formed: 15 patients with large V waves and significant mitral regurgitation, 15 patients with large V waves with no significant mitral regurgitation, and 35 patients with small V waves. The mPCWP and left ventricular end-diastolic pressure were greatest in the group with large V waves and no significant mitral regurgitation. Peak early diastolic TMF and PVF velocities were significantly greater in the two groups with large V waves. The peak second systolic PVF velocity was lowest in the group with large V waves and significant mitral regurgitation, followed by the group with large V waves and no significant mitral regurgitation. The V-mPCWP was positively correlated with the peak early diastolic TMF and PVF velocities and negatively correlated with the peak second systolic PVF velocities. Additionally, mitral regurgitation severity in patients with large V waves and significant mitral regurgitation was positively correlated with the peak early diastolic TMF and PVF velocities and negatively correlated with the peak second systolic PVF velocity.
Conclusions: These results suggest that large V waves in PCWP tracings appear not only in severe mitral regurgitation, but also in any condition with markedly elevated left ventricular end-diastolic pressure. Combined analysis of the TMF and PVF velocity patterns is helpful in determining the etiology of these hemodynamic abnormalities.