[Diabetic cardiomyopathy: preclinical pathology disclosed by the increase in ventricular afterload]

In order to test the importance of the association of diabetes mellitus and arterial hypertension in generating morphological and functional changes of the left ventricle (LV) consistent with a cardiomyopathy, 37 patients, aged 27 +/- 6.7 years, were studied by standard and digitized M-Mode echo: eighteen of them were affected by diabetes mellitus, 11 by arterial hypertension, 8 by diabetes and hypertension. Each group was compared to the others and with a group of 14 normal subjects. In order to verify the importance of increased ventricular after-load in modifying ventricular performance of diabetic patients, changes of the peak rate of systolic and diastolic variation of LV diameter and changes of the peak rate of interventricular septum and posterior wall excursion (IVSE, PWE) were evaluated after methoxamine hydrochloride infusion in 8 diabetic and 6 normal subjects. In diabetics the ratio between ventricular thickness and diameter (h/r) was greater than normal subjects (p less than 0.02); this ratio resulted higher in patients with diabetic rhinopathy who also exhibited an isovolumic diastolic period longer than normal (p less than 0.02). Both h/r ratio and isovolumic diastolic period (IDP) were higher in diabetic-hypertensive group as compared to normals (p less than 0.001), strictly diabetic (p less than 0.01 and p less than 0.001) or hypertensive subjects (p less than 0.01). Diabetic-hypertensive group, exhibited a lowering of the systolic and diastolic peak rate of IVSE (p less than 0.01) as well as of systolic peak rate of PWE as compared to the other three groups (p less than 0.05).