REDUCTION OF LEFT-VENTRICULAR HYPERTROPHY WITH ST-JUDE MEDICAL 19 MM VALVE PROSTHESIS

To determine the permissible range of the St. Jude Medical 19 mm valve (SJM19) as an aortic prosthesis, transvalvular maximal pressure gradi ent (maxPG) and postoperative reduction of left ventricular (LV) hyper trophy were examined in 21 patients (body surface area [BSA] 1.28-1.56 m(2), mean 1.42 m(2)). Doppler echocardiographically measured maxPG a t rest was 31 +/- 16 mmHg, which showed no significant difference from the differences in patients' diseases (aortic regurgitation=AR or ste nosis=AS), or BSA. The maxPG, also measured during dobutamine administ ration when they were less than 40 mmHg at rest, increased significant ly from 21 +/- 11 mmHg to 32.1 +/- 15 mmHg, having no differences from the differences in diseases or BSA. Reduction of LV hypertrophy was a chieved postoperatively (mean postoperative period of ten months), wit h the reduction rates of 26 +/- 19% in LV mass and 21 +/- 15% in LV cr oss-sectional area. No significant differences were found between the reduction rates and the differences in the patients' diseases or BSA. These results indicate that, following the implantation of SJM19, LV h ypertrophy was reduced in patients with AR as well as with AS, when th eir BSA values were less than 1.6 m(2). However, limited use is recomm ended because the increase in pressure gradient during exercise cannot be ignored.