What is EA ratio?

[Melisa41]

What is EA ratio and what should it be. Mine is 0.70  Is this good? Is high better than low?

[kenkeith]

Clinical features of heart failure, particularly left heart failure and cardiomyopathy includes diastolic pressures as an indictor and increased diastolic filling pressures associated with poor relaxation and decreased compliance. E/A ratio relates to diastolic dysfunction.

For a perspective, isovolumic relaxation time (IVRT, IRT) - this (the time from aortic valve closure to mitral valve opening) is measured by simultaneous Doppler and M-mode echo.  If it's prolonged, it indicates poor myocardial relaxation. A normal IRT is about 70±12 ms, perhaps about 10ms longer in those over forty. With abnormal relaxation, the value is usually in excess of 110ms, with restrictive filling, under 60.

Velocity, the transmitral inflow (E/A; E wave deceleration) The E wave occurs related to LV `suction' (relaxtion, filling phase) and LA pressure - the E wave acceleration will be higher with high LA pressure, and lowered with impaired LV relaxation. Deceleration of inflow of the E wave is measured by deceleration time (DT), which shortens with decreasing LV compliance. DT is rather complex, as higher LA pressures shorten it. A normal DT is about 200±32ms; values over 240ms indicate impaired relaxation, and under 150ms suggest restriction. There are a lot of problems with relying on E/A ratios, as the effects of impaired relaxation and restriction counterbalance one another, resulting in 'pseudonormalisation'.

Normally, early filling exceeds the atrial component of filling, and so the mitral inflow velocity profile shows a bigger E than A wave. With impaired relaxation, the E component will be reduced, resulting in a lower E:A ratio. Conversely, with a restrictive pattern, the E component is said to be increased , resulting in an abnormally high E:A.

MILD DYSFUNCTION  (E/A under 1, IVRT over 100ms (time from MV closing to aorta opening), normal E wave deceleration, atrial reversal of pulmonary venous inflow < 0.35 m/s), to mild...MODERATE  diastolic dysfunction (similar E/A and IVRT, but atrial reversal over 0.35, and over 20ms greater than mitral A wave duration)
moderate disease ("pseudonormalisation" --- apparently normal E/A, atrial reversal over 0.35) . Severe dysfunction ("restrictive" --- large E and small A, short E deceleration of under 120ms, short IVRT, reduced pulmonary systolic wave)

Which is better low E:A ratio or high E:A ratio?  Both conditions will cause diastolic dysfunction?  In some conditions, either impaired relaxation (e.g. hypertrophic cardiomyopathy) or restriction (restrictive cardiomyopathies, for example) may prevail. With impaired relaxation, early filling is impaired; conversely, with a restrictive pattern, the E/A ratio increases , as early filling is favored! If both are present, then we have the dreaded "pseudonormalisation".