TRANSESOPHAGEAL AND TRANSTHORACIC ECHOCAR DIOGRAPHIC EVALUATION OF THE MECHANISM AND QUANTIFICATION OF REGURGITATION IN MITRAL AND AORTIC BIOPROSTHETIC VALVES

The respective values of transoesophageal (TOE) and transthoracic echo cardiography (TTE) in the evaluation of the mechanism and the quantifi cation of pathological regurgitation of bioprosthetic heart valves wer e analysed in 23 patients (14 mitral, 9 aortic ; duration of implantat ion 108 +/- 43.2 months). Surgical or pathological correlations were a vailable in all cases and catheter data in 18 of the 23 patients. With regards to mitral bioprostheses, the TOE evaluations of the mechanism and site of regurgitation corresponded in all cases with the operativ e or pathological findings and quantification of mitral regurgitation concorded with angiography. There was an underestimation of the severi ty of mitral regurgitation in 30 % of cases by TTE compared with angio grapbhy ; prolapse was diagnosed in 7 of the 10 cases with cusp tears. It was not possible to accurately determine the intra or perivalvular site of regurgitation by TEE. With regards to aortic bioprostheses, T OE and TTE were equally useful in determining the mechanism of regurgi tation, showing cusp prolapse in 6 of the 9 cases with cusp tears. How ever, TTE quantified regurgitation accurately in all cases with respec t to angiography, whereas TOE was only contributive in 50 % of cases. These results show that single plane TOE is superior to TTE in the qua ntification and determination of the mechanism of regurgitation in mit ral bioprostheses, but that TTE remains better for the quantification of regurgitation of aortic bioprostheses.