Effect of balloon aortic valvuloplasty on the dynamics of left ventricular ejection.

Abstract

To evaluate the effect of balloon aortic valvuloplasty on left ventricular ejection dynamics, simultaneous left ventricular and aortic pressures were obtained by use of a micromanometer catheter in nine patients before and after the procedure. Ejection times, stroke volumes (thermodilution), ejection rates, and pressure gradients were measured. For each parameter, ejection was then divided into two components: accelerative (onset systole to peak gradient) and decelerative (peak gradient to end systole). After valvuloplasty, there was 1) a decrease in overall ejection time and in mean and peak pressure gradients; 2) an increase in overall ejection rate; 3) no change in stroke volume or heart rate; 4) an increase in both accelerative and decelerative ejection rates and a decrease in the decelerative ejection time (expressed as a percentage of the R-R interval); and 5) a decrease in the time for the ejection of the final 25% of stroke volume (P less than 0.01) and time occupied by the final 25% of the gradient. Immediately following balloon aortic valvuloplasty, there is a decrease in ejection time and in increase in ejection rate. Balloon aortic valvuloplasty has a significant effect on the dynamics of left ventricle ejection, with changes primarily expressed in late systole. By improving the mobility of calcified leaflets, balloon aortic valvuloplasty may reduce the forces opposing forward blood movement during the decelerative phase of ejection.