POSTOPERATIVE HEMODYNAMICS OF 2 BILEAFLET HEART-VALVES IN THE AORTIC POSITION

Background and aims of the study: In vivo hemodynamic assessment of bi leaflet aortic valve prostheses using standardized echocardiography is still uncommon; hence, adequate comparison of valve types can rarely be made. We compared the postoperative hemodynamics of St. Jude Standa rd valves (SJS) with those of Sorin Bicarbon valves (BC) implanted in the aortic position, using pulsed, continuous and color Doppler echoca rdiography. Methods: The examination was performed four months after a ortic valve prosthesis implantation in 76 patients (39 SJS valves, 37 BC valves). Valve sizes varied from 19 mm to 25 mm. Maximal and mean i nstantaneous pressure gradients were measured by Doppler echocardiogra phy. Effective valve orifice area(EOA) was calculated and prosthetic v alve regurgitation was assessed by color Doppler flow imaging. Results : At valve sizes of 21 mm 23 mm and 25 mm, SJS valves had a significan tly lower EOAs than BC valves (p<0.05). However, for a given nominal s ize, BC valves are larger, i.e. they have a larger anatomic (AOA) and geometric orifice area (GOA) than SJS valves. Consequently, PC valves were implanted in patients with a larger left ventricular outflow trac t (p<0.05). When EOA is related to the corresponding AOA, BC valves st ill show a larger EOA than SJS valves (p<0.05). Prosthetic valve regur gitation is low in both valve types. Conclusions: (a) Nominal valve si ze is not always a good basis for comparison of hemodynamic profiles b etween valve types. (b) Using the relationship between EOA and AOA, th e hemodynamic profile of PC valves in the aortic position is shown to be superior to that of SJS valves.