Importance of mitral subvalvular apparatus in terms of cardiac energetics and systolic mechanics in the ejecting canine heart.

Abstract

Introduction

Importance of Mitral Valve Second-Order Chordae for Left Ventricular Geometry, Wall Thickening Mechanics, and Global Systolic Function

“…Analysis of PRSW (another load-insensitive measure of LV systolic performance that incorporates both systolic and diastolic information) showed that the SW-EDV relation was highly linear (Figure 2b) and decreased after chordal cutting, again reflecting reduced global pump function. 5,21 The mechanisms responsible for second-order chordae valvular-ventricular interaction may be related to their importance in maintaining elliptical LV geometry and enhancing regional LV wall thickening. Our results demonstrate a link between the second-order chordae and LV structure and function, consistent with previously published works.…”

“…The importance of mitral papillary-annular continuity for optimal global LV systolic performance, a concept we have previously termed "valvular-ventricular interaction," 2 has been demonstrated in clinical studies showing improved patient outcomes and LV performance after chordal preservation during mitral valve replacement 3,4 and in experimental studies documenting global LV contractile dysfunction after transection of all chordae. 2,5 Mitral valve repair is associated with superior survival and improved LV function compared with replacement, 6,7 in part because the entire subvalvular apparatus is preserved. 4 Although the importance of chordal preservation for LV systolic function during valve replacement is widely accepted, the selective roles of first-order versus second-order chordae have only recently been explored.…”

Development of a Simultaneous Cryo-Anchoring and Radiofrequency Ablation Catheter for Percutaneous Treatment of Mitral Valve Prolapse

“…9 The benefit of MV repair is that it preserves the sub-valvular apparatus, consisting of the chords and papillary muscles, as removal of these structures has been associated with detrimental effects on left ventricular shape and performance. 19,46 However, recent rates of repair in those who required MV surgery were as low as 44% in the United States, 39 indicating that the complexity of valve repair makes treatment difficult, and more improved techniques will be necessary to improve repair rates.…”

Effect of disrupting the mitral apparatus on left ventricular function in dogs.

“…The (7) The stroke work-end-diastolic volume relation was determined as another measure of contractility29'30 during each caval occlusion using linear regression to fit: SW=Ssw(Ved Vsw) (8) where S,, is the slope of the linear stroke work-end-diastolic volume relation, and V0,,, is the volume-axis intercept.…”