Mitral flow is assessed by placing the Doppler cursor just distal to the mitral valve in apical four chamber view. Two diastolic waves, E and A are seen in normal mitral Doppler. The E wave is early diastolic and A wave occurs during atrial systole. A wave is absent in atrial fibrillation. Normally E wave is taller than A wave. A wave becomes prominent in diastolic dysfunction of the left ventricle. This leads to E/A reversal. E/A reversal is the most commonly used index of left ventricular diastolic dysfunction during routine echocardiography, though it has several limitations.
In restrictive filling pattern of the left ventricle, E wave is tall, more than 1.5 times the A wave. This is also a pattern of diastolic dysfunction of the left ventricle. The E wave in this case has a fast deceleration slope. E waves can be tall in the presence of severe mitral regurgitation .