In vitro simulation of regurgitant jets demonstrated that jet penetration decreases as chamber diameter decreases, pulsatility index increases, and momentum ratio decreases.
In vitro simulation demonstrates that regurgitant jet size is influenced by chamber diameter, pulsatility, and momentum ratio, explaining why jet size is not always a reliable estimate of regurgitant severity.
Mitral and tricuspid regurgitation create turbulent jets within the atria. Clinically, for the purpose of estimating regurgitant severity, jet size is assumed to be proportional to peak jet flow rate and regurgitant volume. Unfortunately, the relationship is more complex because the determinants of jet size include interactions between jet pulsatility, jet momentum, atrial width, and the velocity of ambient atrial counterflows. These effects on fluorescent jet penetration were measured using an in vitro simulation. Both steady and pulsatile jets were driven into an opposing counterflow velocity field peak jet length (Ljp) measurements made as a function of (1) peak orifice velocity (Ujp), (2) the time required for the jet to accelerate from zero to peak velocity and begin to decelerate (Tjp), (3) jet orifice diameter (Dj), (4) counterflow velocity (Uc), and (5) counterflow tube diameter (Dc). A compact mathematical description was developed using dimensional analysis. Results showed that peak jet length was a function of the counterflow tube diameter, the ratio of peak jet to counterflow momentum, (Mjp/Mc) = (U2jpD2j)/(U2cD2c), and a previously undescribed jet pulsatility parameter, the pulsatility index (PI), PI = D2c/(TjpUjpDj). For the same jet orifice flow conditions, jet penetration decreased as chamber diameter decreased, as the jet PI increased, and as the momentum ratio decreased. These interactions provide insight into why regurgitant jet size is not always a good estimate of regurgitant severity.
Grimes et al. (Fri,) conducted a other in Mitral and tricuspid regurgitation. In vitro simulation of jet pulsatility, momentum, and counterflows was evaluated on Peak jet length (Ljp). In vitro simulation of regurgitant jets demonstrated that jet penetration decreases as chamber diameter decreases, pulsatility index increases, and momentum ratio decreases.