A three-component force vector cell for in vitro quantification of the force exerted by the papillary muscle on the left ventricular wall

Recent clinical studies indicate that functional mitral regurgitation, which is a common complication in patients who suffer from ischemic heart disease, is related to an increase in the tethering forces acting on the mitral valve leaflets. Alterations in the valvular assembly, displacement of the papillary muscles or dilatation of the mitral valve annulus can disrupt the normal force balance on the mitral leaflets and result in an abnormal coaptation geometry with incomplete mitral leaflet closure. The force balance imposed on the mitral leaflets is created by the coapting forces generated by the transmitral pressure difference and the tethering forces at the leaflet attachments. A unique force vector cell capable of accurately measuring the three-component force vector applied by the papillary muscle on the left-ventricular wall was designed and manufactured to permit quantification of the alteration in the force balance acting on the mitral leaflets, and to allow for the study of the influence of papillary muscle displacement on mitral regurgitation. (C) 1997 Elsevier Science Ltd.