A slow Y descent may be seen in tricuspid stenosis and right atrial myxoma.
A sharp Y descent may be seen in right ventricular failure.
A more dramatic Y descent may be seen in constrictive pericarditis with a calcified pericardium, and in tricuspid regurgitation.
Friedreich's sign describes a rapid fall and rise in the JVP. It occurs when stiff ventricles are unable to accommodate the rapid ventricular filling that should follow opening of the tricuspid valve in the presence of elevated atrial pressure.