Because the formula for the cross-sectional area involves the square of the radius, any error in measuring the left ventricular outflow tract may create a substantial error in flow calculation. A 2-mm error in measuring a 2.0-cm diameter outflow tract will result in an approximate 20% error in the flow volume calculation.
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Usar esta medida imprecisa para definir a estenose valvar aórtica é muito arriscado.
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