Ischemia-Induced Malcoaptation of Scallops within the Posterior Mitral Leaflet
Truls Myrmel MD, David T. M. Lai FRACS, Sidney Lo MD, Tomasz A. Timek MD, David Liang MD, D. Craig Miller MD, Neil B. Ingels, Jr., PhD, George T. Daughters MS

Miniature radio-opaque markers were attached to the mitral annulus and posterior mitral leaflet scallops in eight sheep. Three-dimensional coordinates of the markers were obtained by biplane videofluoroscopy before and during echocardiographically verified acute ischemic mitral regurgitation. Analysis showed that during systole, the mean (±SD) distance between the central and anterolateral markers, both placed on the central scallop of the posterior mitral leaflet, was unaffected by ischemia (7.4 ± 2.4 versus 7.4 ± 2.5 mm; p = NS). In contrast, the systolic distance between the central scallop marker and the posteromedial scallop marker increased in three hearts with the posteromedial marker on the posteromedial scallop. There was no separation in five hearts having both the central and posteromedial markers on the central scallop itself. This separation of the central and posteromedial scallops during acute ischemia suggests that the concept of inter-leaflet malcoaptation should also be expanded to include malcoaptation within the posterior leaflet.