INTRODUCTION AND OBJECTIVES: We investigated the anatomical localization, biomechanical properties, and molecular phenotype of myocardial collagen tissue in 40 @entity1 with severe @entity472 with preserved ejection fraction and symptoms of @entity712 . METHODS: Two transmural biopsies were taken from the left ventricular free wall. Mysial and nonmysial regions of the collagen network were analyzed. Myocardial collagen volume fraction (CVF) was measured by picrosirius red staining. Young's elastic modulus (YEM) was measured by atomic force microscopy in decellularized slices to assess stiffness. Collagen types I and III were measured as CIVF and CIIIVF, respectively, by confocal microscopy in areas with YEM evaluation. RESULTS: Compared with controls, @entity1 exhibited increased mysial and nonmysial CVF and nonmysial:mysial CVF ratio (P < .05). In @entity1 , nonmysial CVF (r = 0.330; P = .046) and the nonmysial:mysial CVF ratio (r = 0.419; P = .012) were directly correlated with the ratio of maximal early transmitral flow velocity in diastole to early mitral annulus velocity in diastole. Both the CIVF:CIIIVF ratio and YEM were increased (P <=  .001) in nonmysial regions compared with mysial regions in @entity1 , with a direct correlation (r = 0.895; P < .001) between them. CONCLUSIONS: These findings suggest that, in @entity1 with severe @entity472 with preserved ejection fraction and symptoms of @entity712 , @entity67 is associated with increased nonmysial deposition of collagen, predominantly type I, resulting in increased extracellular matrix stiffness. Therefore, the characteristics of collagen tissue may contribute to @entity67 in these @entity1 .

Role of Myocardial Collagen in Severe XXXX With Preserved Ejection Fraction and Symptoms of @entity712 .

@entity1 :: ('9606', 'Species') :: ['patients'] @entity472 :: ('MESH:D001024', 'Disease') :: ['aortic stenosis'] @entity712 :: ('MESH:D006333', 'Disease') :: ['heart failure'] @entity67 :: ('MESH:D018754', 'Disease') :: ['diastolic dysfunction']
@entity472 :: (MESH:D001024,Disease) :: ['Aortic Stenosis']
