Afterload changes in diabetic dysautonomia evaluated using echocardiography

We have studied echocardiographic morpho-functional alterations in 34 male subjects with diabetes, aged 31-73 years, with and without autonomic nervous system failure. The subjects are grouped following the tests "deep breathing", "Valsalva manoeuver", "lying to standing" and "active standing" in: D-I (10 normal subjects); D-II (16 subjects with parasympathetic failure); D-III (8 subjects with orthosympathetic failure). The D-III subjects showed significantly lower parietal systolic stress (PSS) compared to normal subjects, 115.6 +/- 17.4 vs 163.1 +/- 13.1 10(3) dynes/cm2 (mean +/- 1SD), and significantly lower end isovolumetric systolic stress, 67.8 +/- 7.8 vs 98.6 +/- 7.1 10(3) dynes/cm2 ("afterload" indexes). In D-III group, the subjects with noradrenaline levels greater than 300 pg/ml, with an hypothetical peripheral resistance to noradrenaline (or receptor "down regulation"), showed higher blood pressure levels and higher parietal stress (PSS: 141.3 +/- 25.3 vs 98.5 +/- 20.7 10(3) dynes/cm2; EISS: 74.1 +/- 17.8 vs 63.6 +/- 8.6 10(3) dynes/cm2). Thus, cardiovascular signs of autonomic failure, like the stress index variation, related to a modification of the afterload, may be observable in diabetic patients.