A calculated left ventricular stroke work loss of ≥30% was associated with an aortic valve area of ≤1.0 cm2, indicating serious obstruction to left ventricular outflow.
Observational (n=49)
Does the percentage of left ventricular stroke work loss correlate with aortic valve area in subjects with aortic stenosis?
The percentage of left ventricular stroke work loss is a simple calculation based on pressure pulses that reliably indicates the severity of left ventricular outflow obstruction.
The ratio of the mean systolic transaortic valvular gradient to the mean systolic left ventricular pressure times 100 yields a percentage that represents the portion of left ventricular pressure-volume work per stroke lost because of outflow-tract obstruction. The percentage of the left ventricular stroke work loss and the area of the aortic orifice have been estimated in 49 patients with aortic valvular stenosis and two open-chest dogs with varying degrees of supravalvular aortic constriction. Left ventricular stroke work loss of 30% or greater was associated with calculated aortic valve areas of 1.0 cm 2 (or 0.60 cm 2 /m 2 ) or less. These values are representative of serious obstruction to left ventricular outflow, that is, approximately 75% or greater reduction of normal orifice size. The calculation of the percentage of left ventricular stroke work loss, besides being simple, is based upon the most reliable measurements obtainable at left heart catheterization, that of the pressure pulses.
Tobin et al. (Mon,) conducted a observational in Aortic valvular stenosis (n=49). Calculation of percentage of left ventricular stroke work loss vs. Calculated aortic valve area was evaluated on Association between left ventricular stroke work loss and aortic valve area. A calculated left ventricular stroke work loss of ≥30% was associated with an aortic valve area of ≤1.0 cm2, indicating serious obstruction to left ventricular outflow.
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