[Use of heart rate variability and pulse wave velocity for diagnosing cardiovascular autonomic neuropathy]

Heart rate (HR) and arterial pulse wave velocity (PWV) were used for the evaluation of cardiovascular autonomic neuropathy. Data were analyzed from 30 patients with diabetes mellitus (aged from 13 to 75 years). Twenty healthy male subjects (aged from 22 to 44 years) were analyzed for computing normal values as well. After 15 minutes rest, electrocardiogram (ECG) of lead II and plethysmogram of finger tip were simultaneously recorded for each subject. The recording was first done in supine position for 120 seconds and subsequently in upright position for 40 seconds. HR was computed on the basis of consecutive pairs of R wave of the ECG. PWV was estimated by transit time from R wave peak to initial rise of pulse wave. Mean and coefficient of variation (CV) were obtained from the HR in the supine and upright positions respectively, and also from the PWVs. The influence of changing the position was evaluated by percentage of the difference (increasing rate). All the parameters were statistically tested for the difference between the patients with neuropathy and those without neuropathy. As the result, two parameters, that is, the CV of HR in the supine position and the increasing rate of PWV were found to be useful for diagnosing the cardiovascular autonomic neuropathy (p less than 0.05).