Standardization of a computerized method for calculating autonomic function test responses in healthy subjects and patients with diabetes mellitus

Abstract

The objectives of the present study were 1) to compare results obtained by the traditional manual method of measuring heart rate (HR) and heart rate response (HRR) to the Valsalva maneuver, standing and deep breathing, with those obtained using a computerized data analysis system attached to a standard electrocardiograph machine; 2) to standardize the responses of healthy subjects to cardiovascular tests, and 3) to evaluate the response to these tests in a group of patients with diabetes mellitus (DM). In all subjects (97 healthy and 143 with DM) we evaluated HRR to deep breathing, HRR to standing, HRR to the Valsalva maneuver, and blood pressure response (BPR) to standing up and to a sustained handgrip. Since there was a strong positive correlation between the results obtained with the computerized method and the traditional method, we conclude that the new method can replace the traditional manual method for evaluating cardiovascular responses with the advantages of speed and objectivity. HRR and BPR of men and women did not differ. A correlation between age and HRR was observed for standing (r = -0.48, P<0.001) and deep breathing (r = -0.41; P<0.002). Abnormal BPR to standing was usually observed only in diabetic patients with definite and severe degrees of autonomic neuropathy.

Inspiratory muscle weakness is associated with autonomic cardiovascular dysfunction in patients with type 2 diabetes mellitus

“…Also, as the same medications were used by the patients in both studied groups, the medication in use did not influence the present results. The diagnosis and classification of diabetic autonomic neuropathy were based on classical tests as proposed by Ewing [10] because they are easy-to-perform, non-invasive standardized tests in our setting [24]. In subjects with diabetic autonomic neuropathy, absolute (cmH 2 O) and relative PImax values (% of predictive) were 22% lower than those seen in subjects without diabetic autonomic neuropathy.…”

“…The presence of diabetic autonomic neuropathy was verified using the classic Ewing autonomic function tests, as previously described [10] and standardized in our institution [24], which were performed as follows: (1) Basal HR was evaluated after the subject had been lying down for 15 min. Then HR rate response to deep breathing was tested: the subject breathed deeply and evenly at a rate of 6 breaths/min, while the examiner informed the subject when each period of 5 s was ending and when to inhale and exhale.…”

“…The BP variation between when the person was lying down and one minute after standing up was taken as the change in postural BP, measured with an aneroid sphygmomanometer. Patients were classified according to the number of abnormal tests: when all of them were normal the patient was considered not to have neuropathy; one abnormal test-early involvement; two or three abnormal tests-moderate involvement; four abnormal tests-severe involvement [24].…”

A Comparative Study of Heart Rate Variability in Diabetic Subjects and Normal Subjects

“…1, 8,18. The new method can replace the traditional manual method for evaluating cardiovascular responses with the advantages of speed and objectivity. 8 Analysis of 5 minutes measurements of heart rate variability (HRV) has been shown to be a good predictor of physiological distress and mortality, especially for cardiovascular disease. 5,12,16,21,24,25 Diabetes is an ICEBERG disease.…”

Physiological variations in the autonomic responses may be related to the constitutional types defined in Ayurveda

“…4) Calculation of Valsalva Raio: The Valsalva ratio is calculated as the ratio of the longest RR interval after manoeuvre to shortest R-R interval during manoeuvre. A value > 1.21 is taken as normal and a value less than that is indicative of parasympathetic insufficiency (Neumann and Schmid, 1997).…”