New contribution to the study of ventricular remodeling and valve rings in dilated cardiomyopathy: anatomical and histological evaluation

Introduction

Idiopathic dilated cardiomyopathy causes great impact but many aspects of itspathophysiology remain unknown.

Objective

To evaluate anatomical and histological aspects of hearts with idiopathic dilatedcardiomyopathy and compare them to a control group, evaluating the behavior of theperimeters of the atrioventricular rings and ventricles and to compare thepercentage of collagen and elastic fibers of the atrioventricular rings.

Methods

Thirteen hearts with cardiomyopathy and 13 normal hearts were analysed. They weredissected keeping the ventricular mass and atrioventricular rings, with laminationof segments 20%, 50% and 80% of the distance between the atrioventricular grooveand the ventricular apex. The sections were subjected to photo scanning, withmeasurement of perimeters. The atrioventricular rings were dissected and measureddigitally to evaluate their perimeters, later being sent to the pathologylaboratory, and stained by hematoxylin-eosin, picrosirius and oxidized resorcinfuccin.

Results

Regarding to ventricles, dilation occurs in all segments in the pathologicalgroup, and the right atrioventricular ring measurement was higher in idiopathicdilated cardiomyopathy group, with no difference in the left side. With respect tocollagen, both sides had lower percentage of fibers in the pathological group.With respect to the elastic fibers, there was no difference between thegroups.

Conclusion

There is a change in ventricular geometry in cardiomyopathy group. The leftatrioventricular ring does not dilate, in spite of the fact that in bothventricles there is lowering of collagen.