EVALUATION OF THE CARDIAC AUTONOMIC NERVOUS SYSTEM THROUGH DYNAMIC EXERCISE AND ITS RELATIONSHIP TO RIGHT VENTRICULAR DIASTOLIC FUNCTION IN PATIENTS WITH TYPE I DIABETES MELLITUS.

Abstract

BACKGROUND: Subclinical right ventricular diastolic dysfunction (RVVDD) is prevalent in
the population of patients with type 1 diabetes mellitus (DM1). However, the association between
cardiac autonomic neuropathy (CAN) and RVVDD has not been studied.
To study in type 1 diabetic patients the association between CAP and the presenceof impaired right
ventricular diastolic function.
MATERIALS AND METHODS: An observational, analytical, cross-sectional study was carried
out in 48 patients, 25 with DM1 and 23 control subjects without DM1. All patients underwent
determination of glycosylated hemoglobin (HbA1c), fasting blood glucose, B-mode
echocardiogram - Doppler, and Tissue Doppler (TDI) and the Valsalva test as a Cardiac
Autonomic Reflex Test (CART). Similarly, the resting heart rate was evaluated and through the
performance of a stress test the HR acceleration was determined 10 seconds after the start of
exercise and the HR recovery deltas (HRR) at the 1st and 2nd minute after the end of exercise.
RESULTS: Right ventricular diastolic dysfunction was present in 13 of the patients with DM1
corresponding to 52% manifested by an altered E/e ratio (p 0.039). The Valsalva index ratio was
lower in 14 of the diabetic patients (56%) in relation to non-diabetic controls with statistically
significant difference (1.31 ± 0.14 vs 1.50 ± 0.082 p 0.0001). CFR was found significantly altered
in diabetics compared to controls (delta at 1st min p 0.01, delta at 2nd min p .0001). Logistic
analysis showed that the Valsalva index was the independent variable of highest value with the
presence of DDVD since all 13 diabetic patients with DDVD had abnormal Valsalva index.
Correlation was obtained between the Valsalva test and the E/e' ratio with glycosylated Hb and
fasting glycemia, with a direct, positive and significant linear relationship of the Valsalva index
with glycosylated Hb (r = 0.829; p = 0.0001) and for its part the E/e' ratio showed a direct and
positive linear relationship with glycosylated Hb (r = 409; p = 0.042).
CONCLUSION: The alteration of the cardiac autonomic nervous system manifested mainly by
an abnormal Valsalva index ratio was associated with DDVD. and in turn this variable was
associated with poor metabolic control.