Simplified Bernoulli formula may not be applicable for the measurement of transvalvular gradients if LV outflow tract velocity is elevated.

Peak aortic jet velocity and mean gradient may: (1) overestimate AS severity in presence of significant AR due high transvalvular flow; and (2) underestimate AS severity in presence of depressed LVEF and low flow state.

Continuity equation is valid for the calculation of effective AVA in the context of MAVD.

Anatomic AVA measured by planimetry is often smaller than effective AVA due to flow contraction phenomenon. Anatomic AVA may thus underestimate AS haemodynamic severity.

AVA and DVI are the best parameters to assess the severity of AS in the context of MAVD. These parameters may overestimate AS severity in presence of low flow state.

Not recommended in clinical practice.

Anatomic AVA measured by planimetry using contrast MDCT is often smaller than the effective AVA due to flow contraction phenomenon. Anatomic AVA may thus underestimate AS severity. This technique is associated with a high radiation dose. Non-contrast CT for assessment of AVC score can be achieved with a lower radiation dose.

Effective AVA cannot be measured by MDCT.

AVA by Gorlin formula using thermodilution or Fick methods is not valid in the presence of MAVD.

AR pressure half time may overestimate AR severity in patients with MAVD due to frequent concomitant LV diastolic dysfunction.

Timing and end-diastolic velocity of the flow reversal in the descending aorta may overestimate AR severity in patients with MAVD due to frequent concomitant reduced aortic compliance.

VC width, EROA and RV may underestimate AR severity in the context of MAVD. RF may be preferable to assess AR severity in MAVD.

CMR may be used to corroborate RV and RF.

RV may underestimate AR severity in the context of MAVD. RF may be preferable to assess AR severity in MAVD.

Aorta angiography may be used to assess AR severity but is dependent on technique, operator and amount of injected contrast.

Peak aortic jet velocity and mean gradient are the best parameters to assess the overall haemodynamic severity of MAVD.

Peak aortic jet velocity and mean gradient may underestimate MAVD severity in presence of low flow state.

AVC score by non-contrast MDCT may be used to assess the overall severity of MAVD.

AVC should be interpreted with caution in younger patients, especially women, with a bicuspid aortic valve, as this parameter is associated with high rate of false-negative cases.