Idiopathic dilated cardiomyopathy: computerized anatomic study of relashionship between septal and free left ventricle wall

INTRODUCTION: A feature of dilated cardiomyopathy is the deformation of ventricular cavity, which contributes to systolic dysfunction. Few studies have evaluated this deformation bearing in mind ventricular regions and segments of the ventricle, which could reveal important details of the remodeling process, supporting a better understanding of its role in functional impairment and the development of new therapeutic strategies. OBJECTIVE: To evaluate if, in basal, equatorial and apical regions, increased internal transverse perimeter of left ventricle in idiopathic dilated cardiomyopathy occurs proportionally between the septal and non-septal segment. METHODS: We performed an anatomical study with 28 adult hearts from human cadavers. One group consisted of 18 hearts with idiopathic dilated cardiomyopathy and another group with 10 normal hearts. After lamination and left ventricle digital image capture, in three different regions (base, equator and apex), the transversal internal perimeter of left ventricle was divided into two segments: septal and not septal. These segments were measured by proper software. It was established an index of proportionality between these segments, called septal and non-septal segment index. Then we determined whether this index was the same in both groups. RESULTS: Among patients with normal hearts and idiopathic dilated cardiomyopathy, the index of proportionality between the two segments (septal and non-septal) showed no significant difference in the three regions analyzed. The comparison results of the indices NSS/SS among normal and enlarged hearts were respectively: in base 1.99 versus 1.86 (P=0.46), in equator 2.22 versus 2.18 (P=0.79) and in apex 2.96 versus 3.56 (P=0.11). CONCLUSION: In the idiopathic dilated cardiomyopathy, the transversal dilatation of left ventricular internal perimeter occurs proportionally between the segments corresponding to the septum and free wall at the basal, equatorial and apical regions of this chamber.