Echocardiographic and phonocardiographic characteristics of the lillehei-kaster mitral valve prosthesis.

SUMMARY The Lillehei-Kaster (L-K) valve is a tilting disc prosthesis currently in use for heart valve replacement. We report data from phonocardiography (PHONO) and echocardiography (ECHO) in 20 patients with a normally functioning mitral valve prosthesis (MVP). The MVP is well recorded by ECHO, resembling a mitral stenosis pattern with a disc excursion of 7 to 12 mm and a mean opening and closing velocity of 37.7 and 59.8 cm/sec, respectively. Combined PHONO and ECHO show that the opening sound of the MVP is small, related to onset of valve opening and not peak opening. It follows the aortic component of the second sound (A2) by 0.05 to 0.09 sec in normals; it may be absent (12/20). Peak opening follows A2 by 0.08 to 0.12 sec. The closing sound of the MVP, best heard in the mitral area, is always twofold with a small initial high frequency (HF) component and a second large HF sound separated by no more than 0.03 sec. The first component (A) is related to onset of closure and the second (B) to completion of closure. Systolic and diastolic murmurs were commonly present. These data establish the normal ECHO and PHONO findings for patients with L-K MVP. Two other patients are also reported in whom such data were helpful for the noninvasive evaluation of valve function, indicating in one instance acute mitral regurgitation and in the other an increase in degree of aortic regurgitation. Mitral valve surgery Prosthesis T' HE ANALYSIS of prosthetic valve dynamics by noninvasive means has become an acceptable way of assessing the functional status of several varieties, notably the Starr-Edwards series. Phonocardiography and, recently, echocardi-ography have been used for this purpose giving helpful information which can contribute to the identification of malfunction. During the past 18 months, we have been using the Lillehei-Kaster valve, an eccentric monocusp central flow prosthe-SiS.1' 2 This valve prosthesis is now in general use and, in order to obtain baseline data for the evaluation of function, we have delineated the phonocardiographic and echocardiographic characteristics of the mitral prosthesis. The manner in 434 which certain complications may be diagnosed by those relatively simple methods has also been considered. Materials and Methods The study includes 22 patients aged 15 to 63. All had mitral valve replacement for either mitral stenosis or insufficiency but four also had aortic valve replacement. At operation, the mitral valve prostheses were placed so that …