Comprehensive echocardiographic assessment of mechanical tricuspid valve prostheses based on early post-implantation echocardiographic studies

Background: Doppler-derived hemodynamic data for normal tricuspid mechanical valve prostheses are limited.

Methods: A comprehensive retrospective Doppler echocardiographic assessment of 78 normal St. Jude Medical Standard (St. Jude Medical, Inc., St. Paul, MN), CarboMedics Standard (CarboMedics, Inc., Sorin Group, Burnaby, British Columbia, Canada), and Starr-Edwards (Edwards Lifesciences, LLC, Irvine, CA) mechanical tricuspid valve prostheses was performed early after implantation. We used all the important Doppler-derived hemodynamic variables reported to date, including peak early diastolic velocity (E velocity), mean gradient, pressure half-time, time velocity integral of the tricuspid valve prosthesis (TVI(TVP)), and ratio of the time velocity integral of the tricuspid valve prosthesis to the time velocity integral of the left ventricular outflow tract (TVI(TVP)/TVI(LVOT)).

Results: The mean values obtained for the Doppler parameters did not differ significantly when the measurements from five or nine consecutive cardiac cycles were averaged. Pressure half-time was <130 msec in all 43 patients with St. Jude Medical Standard and CardioMedics Standard prostheses in whom it could be measured. Mean gradient <6 mm Hg, E velocity <1.9 m/s, TVI(TVP) <46 cm, and TVI(TVP)/TVI(LVOT) <2.1 were recorded in 59 (87%) of the 68 patients with either of these prostheses. Hemodynamic variables were considerably less favorable in patients with Starr-Edwards prostheses.

Conclusion: These calculated threshold values (mean + 2 SD) are useful for identifying normal tricuspid mechanical valve function. Prostheses with values for hemodynamic variables that are outside the mean + 2 SD parameters that we have calculated are most likely to be dysfunctional. However, in rare cases, mechanical tricuspid valve prostheses may be dysfunctional even when their hemodynamic parameters are within these specified ranges because of small body surface area or other factors.