Echocardiographic identification and analysis of function of the St. Jude medical heart valve prosthesis.

The St. Jude medical (SJM) heart valve prosthesis presents a new bi-leaflet design which in preclinical evaluation exhibited favourable haemodynamic characteristics. Therefore clinical trials started in February 1978. The entire valve is made of pyrolytic carbon which has a poor X-ray visibility and therefore an alternative for the noninvasive routine control of valvular function and postoperative follow-up had to be found. Experimental studies in a left heart simulator provided adequate echovisualisation of both leaflets, however, depending on the direction of their motion in relation to the echobeam. Identification of both leaflets and an analysis of their motion was possible with a transducer at right angles to the leaflet axis. The experimental data were confirmed by clinical observations after implantation of the SJM prosthesis in patients. Based on the information obtained, we are providing recommendations for the implantation of the SJM prosthesis in order to achieve optimal echocardiographic visualisation of the valve and its moving parts in the postoperative follow-up.