Noninvasive assessment of the relationship between cardiac and autonomic function in diabetes

In order to assess a possible relationship between left ventricular (LV) function and cardiac autonomic involvement in type-1 insulin dependent diabetes, we performed M-mode echocardiograms and autonomic function tests in 21 patients (mean age +/- SD, 38 +/- 11 years, range 18-55, 16 male and 5 female). In 7 patients and in 21 age-matched controls the echocardiogram was also recorded before and during handgrip. At rest, ventricular function abnormalities were found only in 4 subjects, and no significant correlation was found between echocardiographic parameters and autonomic function tests. Unlike controls, during handgrip diabetic subjects failed to increase peak Vcf and peak filling rate, and increased their left ventricular end-systolic diameter. The changes in LV parameters during handgrip were significantly correlated with resting autonomic function tests (p less than 0.025). Our results suggest that resting cardiac function may be normal in diabetics despite high incidence of abnormal autonomic tests. Latent abnormalities of left ventricular function can be unmasked by acute haemodynamic challenges such as handgrip, and are correlated with abnormalities in autonomic function tests.