Raised JVP and not fall back of JVP is a feature of?

In Atrial fibrillation there is a disorganized, rapid, and irregular atrial activity with the loss of atrial contraction. This insufficient atrial contraction results in accumulation of blood in the atrium, which results in increase in JVP which does not fall back. In ventricular tachycardia, atria empty completely and leads to fall in JVP. In ventricular fibrillation, JVP raises at one time and falls at other time.