Echocardiographic and Phonocardiographic Characteristics of the Lillehei-Kaster Mitral Valve Prosthesis

Abstract

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 two-fold 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.