Pulmonary vein velocities
Pulmonary S-wave velocity (which includes S1 and S2 waves) is impacted by alterations in LA pressure, in addition to LA and LV contractility. D-wave velocity is influenced by early diastolic LV filling and maintains a strong relationship with mitral E velocity.42 The resultant ratio (S/D) is related to changes in compliance of the LA but may have limited accuracy in mitral valve disease.40 In addition, pulmonary vein flow is influenced by obstruction imposed by the valve43 and is less likely to represent changes in LV compliance.