Independent Contribution of Left Ventricular Ejection Time to the Mean Gradient in Aortic Stenosis
Lyes Kadem Eng, Philippe Pibarot DVM, Jean G. Dumesnil MD, Frédéric Mouret Eng, Vincent Garitey PhD, Louis-Gilles Durand Eng, Régis Rieu PhD

Transvalvular mean pressure gradients (MPG) are important in the evaluation of aortic stenosis, but surprisingly they often differ in patients having similar valve effective orifice area and stroke volume. Both in-vitro and in-vivo Doppler echocardiographic data were used to examine how MPG is influenced by physiological variations in left ventricular ejection time (LVET). Results showed that LVET may significantly and independently influence MPG in aortic stenosis. Clinically, variations of up to 15 mmHg in mean gradient may be observed uniquely on the basis of a change in duration of LVET; hence MPG cannot be used as a stand-alone parameter for serial evaluations or for comparisons of aortic stenosis severity between patients.