Aortic Valve Area by Gorlin Equation

Calculate
cm
cm
m/sec
bpm
ms
CO:
AVA:
LOVT DIameter
AV CWD
Formula: CO = 0.785 x LVOTd2 x VTIAV x HR AVG = 4(Vmean)2 AVA = CO / (SEP x HR) / (44.3 x sq root(AVG))

How to calculate a AVA by Gorlin Formula.

  1. Obtain the LVOT Diameter. The ME AVLAX view under zoomed mode is an excellent method to measure the LVOT diameter. Measure the LVOT diameter in mid systole.
  2. Obtain a CWD of the AV. The optimal view is either the DTG AVLAX or TG AVLAX. Once a flow profile is obtained, trace the envelope to calculate the mean velocity (Vmean) and the VTI. From the flow profile the SEP or systolic ejection period can be measured.
  3. Enter the Heart Rate
Modified Gorlin Formula:

AVA = CO / Square Root of Mean AVG.

The cardiac output is in liter per minute.

For example a CO of 5.4 l/min and a mean AVG of 64 yields 5.4 / sq root(64) = 0.68 cm squared.