Resting Aortic Valve Area at Normal Transaortic Flow Rate Reflects True Valve Area in Suspected Low-Gradient Severe Aortic Stenosis

Abstract

Rest AVA measured under normal flow rate conditions is likely to reflect the true severity of AS and unlikely to change significantly with SE. Flow normalization may only be required in patients with AVA <1 cm(2) and mean gradient <40 mm Hg when the rest flow rate is <200 ml/s.

The Utility of Flow Rate Compared with Left Ventricular Stroke Volume Index in the Hemodynamic Classification of Severe Aortic Stenosis with Preserved Ejection Fraction

“…For the interpretation of a given transvalvular gradient and AVA, one may consider FR rather than SVi, because the latter may be normal despite low FR when ET is prolonged, potentially confounding the interpretation of discordant AVA/pressure gradients [12]. One should take into consideration that in addition to a higher AS severity, the ET can be prolonged (and, therefore, FR reduced) in the presence of heart rhythm or intraventricular conduction abnormalities (i.e., bradycardia, left bundle branch block or right ventricular pacing, respectively), whereas the SVi, in the absence of a low SV, can be lowered by increased BSA (i.e., obesity) [18].…”

“…Severe AS was diagnosed according to the contemporary guidelines [11]. A mean gradient ≤40 mm Hg defined “low gradient” and SVi < 35 mL/m 2 defined “low flow.” FR ≥200 mL/s was considered normal [12]. The demographics, and clinical and laboratory data were retrieved from the medical records.…”

“…FR was calculated as SV/ejection time (ET). The ET was measured between the beginning and the end of the aortic flow flanked by the opening and closing click, respectively [12]. AVA was derived from the continuity equation.…”

Transcatheter Aortic Valve Replacement in Low‐Flow Aortic Stenosis: Treat the Flow or Treat the Patient?

“…On the other hand, determination of the flow status by stroke volume index (SVI) has intrinsic limitations. With increasing severity of AS the ejection time may prolong, and even patients with a normal SVI may have reduced transvalvular flow 7. These caveats must be taken into account when measures of AS severity are conflicting.…”

Transvalvular Volume Flow Rate: A Useful Tool for Assessment of Aortic Valve Stenosis in Preserved Ejection Fraction Patients

“…This is the largest study to date that attempted to test the comparative performance of FR compared with SVi in the hemodynamic classification and prognostication of patients with severe isolated AS and preserved EF. Given that FR essentially determines transvalvular gradients, while AVA is relatively independent unless LV dysfunction is present, FR can enable more accurate interpretation of a given gradient/AVA, as, contrary to SVi, it is nondependent on the ejection time [10]. FR can also be superior to SVi in patients with an increased body surface area, when the latter is underestimated [11].…”