987-105 Transesophageal Echocardiographic Quantltation of Systolic Mitral Leaflet Displacement In Patients with Mitral Valve Prolapse

Abstract

While transesophageal echocardiography (TEE) provides detailed structural information about the mitral valve, the range of normal systolic displacement of the mitral leaflets and the best criteria for diagnosing mitral valve prolapse (MVP) by this technique remain controversial. The area subtended by the systolic displacement of the mitral leaflets into the left atrium beyond the annular hinge points on 4 chamber and 2 chamber images of the mitral valve was measured by TEE in a blinded prospective study of 11 MVP pts (who had systolic displacement of the mitral leaflets superior to the mitral annular plane on parasternal long axis images by transthoracic echo and click and/or late systolic murmur on physical exam) and 11 NORMAL subjects (who had no evidence for MVP by either transthoracic echo or exam). Area Subtended by Systolic Displacement of Mitral Leaflets (cm 2 ) 4 Chamber View 2 Chamber View AMV PMV AMV PMV MVP 0.82 ± 0.78 0.40 ± 0.43 1.01 ± 0.99 0.72 ± 0.76 NORMAL 0.03 ± 0.06 ** 0.00 ± 0.00 ** 0.18 ± 0.29 * 0.03 ± 0.05 ** A = anterior, P = posterior, MV = mitral valve ** p < 0.01 * p < 0.02 By TEE the area subtended by the superior displacement of the mitral leaflets into the left atrium was significantly greater for MVP pts than for NORMAL subjects. In NORMAL subjects superior displacement of the PMV was never detected in the 4 chamber view, but small degrees of superior displacement were occasionally detected in the 2 chamber view. As many as 6 of 11 NORMAL subjects exhibited minor degrees of superior displacement of the AMV. If an upper limit of normal of 0.5 cm 2 is set for the total area subtended by both leaflets in both views, this criterion is 100% sensitive and 82% specific forthe diagnosis of MVP. Though TEE demonstrates greater systolic mitral leaflet displacement in MVP than in NORMAl. there is overlap in the range of superior systolic displacement of the mitral valve into the left atrium between MVP pts and NORMAL subjects. The presence of mild superior systolic displacement of the leaflets relative to the annular hinge points by TEE is inadequate to unambiguously identify MVP pts.