Effect of heart rate on mitral valve gradient

Simultaneously recorded pressures from the left atrium (LA) and left ventricle (LV) in a patient with mitral stenosis who has a persistent diastolic gradient (shaded areas) across the mitral valve. Top panel: When the RR interval is shorter, the mean pressure gradient is greater and the mitral valve area smaller. Bottom panel: A long RR interval results in a gradual equilibration of the LA and LV pressures and the mean gradient is smaller. There is no pressure gradient present by the end of diastole.