engleski

Symmetry of the aortic outflow velocity profile in aortic stenosis : does it predict functional changes before and after aortic valve replacement?

Severe aortic stenosis (AS) shows higher, often prolonged LV outflow velocities. The gradient measured over a stenotic valve is indicative of stenosis severity, but often does not relate to myocardial function. We hypothesize a relation between the profile of the aortic outflow velocity and myocardial function. 35 patients undergoing aortic valve surgery for severe AS were studied by echocardiography pre- (PRE) and 1 year postoperatively (POST). 29 healthy volunteers served as controls. Ejection fraction (EF), aortic valve area (AVA) and mean aortic gradient (PG mean) were measured while model-based analysis was applied to aortic CW velocity traces. The asymmetry (asymm) was quantified as the normalized difference of area under the curve of left and right half of the spectrum so that a lower asymm corresponds to more symmetrical, later peaking flow. A significant correlation was found between asymm PRE and change in EF POST-PRE (r=0.66, P<0.05, figure 1, left). Moreover, no correlations were found between AVA nor PG mean and change in EF POST-PRE (r=0.05, r=0.04 ; P>0.05). Asymm PRE did not correlate significantly with PG mean PRE (r=0.18), while the patients with higher values of asymm PRE all showed improvement in EF POST-PRE (positive delta EF), regardless of PG_mean PRE (figure 1, right). A symmetrical aortic outflow profile might reflect not only higher grade AS, but seems related to a reduction in LV function and predicts its recovery after surgery with higher confidence than preoperative mean gradient. Automated model-based analysis provides additional clinical information on the functional impact of AS.

aortic stenosis; echocardiography; haemodynamics; remodelling

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