A V wave in the jugular venous pulse represents venous filling of the right atrium when the tricuspid valve is closed. In severe tricuspid valve regurgitation, there is dramatic accentuation of the jugular V wave (sometimes difficult to distinguish from elevated jugular venous pressure from right heart failure). Similarly, when examining a left atrial (or pulmonary capillary wedge) pressure tracing, the V wave is accentuated in severe mitral regurgitation.
The V wave in the left atrial pressure (LAP) or pulmonary capillary wedge pressure (PCWP) tracing represents left atrial filling against a closed mitral valve. If severe mitral valve regurgitation is present, the V wave will be significantly accentuated. This can be helpful if a patient with an acute inferior MI presents with pulmonary edema and shock to diagnose acute severe mitral regurgitation.