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. 2012 Mar;2(1):19–27. doi: 10.3978/j.issn.2223-3652.2012.01.01

Figure 4.

Figure 4

Importance of LVOT measurements: In the illustrative case the LV EF was 64% and gradients were 52/32 mmHg and AV VTi was 99 cm. Underestimation of LVOT measurements (Panel A, upper) may yield results as follows, LVOT=1.25 cm, CSA of LVOT=1.22 cm2, LVOT VTI=24.7 cm, AVA=0.34 cm2 and iAVA=0.24 cm2/m2. Stroke volume index=17.7 cc/m2 and Zva=10.8 mmHg·m2/cm2. All these measurements indicate low flow, low gradient critically severe AS with rigorously increased afterload. Therefore, valve replacement is mandatory in this patient. However, overestimation of LVOT measurements (Panel B, lower), result as follows LVOT=2 cm, CSA of LVOT=3.14 cm2, LVOT VTI=37 cm, AVA=1.17 cm2 and iAVA=0.7 cm2/m2. Stroke volume index=68 cc/m2 and Zva=2.8 mmHg·m2/cm2. These overestimated results are concluding that this case is normal flow-low gradient which is consistently with moderate AS (based on AVA) and after load is not increased. If the symptomatic status of this patient is unclear, medical therapy with careful follow-up should be recommended. Although the continuity equation is a practical and robust method for the calculation of AVA, this example demonstrates the dependency on measurement of the LVOT.