[The cardiovascular reflex tests in autonomic cardiac neuropathy diagnosis]

Ewing's five standard cardiovascular reflex tests were used for the assessment of autonomic function. Changes in heart rate during deep inspiration and expiration, Valsalva manoeuvre or standing up evaluate parasympathetic innervation, whereas blood pressure fluctuations during standing up and handgrip evaluate sympathetic innervation. According to physiological principles we must remind that each test is useful predominantly but not exclusively to reveal the impairment of parasympathetic or sympathetic innervation. A total of 271 patients (247 with diabetes mellitus) were estimated for the diagnosis of autonomic neuropathy. Computed time domain analysis of the heart rate variability reveals 21% of the patients with autonomic neuropathy, but this method doesn't rich the performance of spectral analysis witch is x3 times greater. The deep inspiration and expiration remains the preferable test according to its sensibility, specificity and predictive value. I found that handgrip test has, beside the known limitations (arterial hypertension, heart failure, valvular disease, emphysema, advanced diabetic retinopathy, drugs like digitalis, beta-receptor blockers, antihypertensives, sedatives, etc.) one more linked by the hand muscular force. Orthostatic hypertension has too many false results so the interpretation must be done with much precaution.