Left Ventricular Diastolic Dysfunction (LVDD) & Cardiovascular Autonomic Neuropathy (CAN) in Type 2 Diabetes Mellitus (DM): A Cross-Sectional Clinical Study.

Abstract

Cardiovascular autonomic neuropathy (CAN) is one of the major complications of Diabetes Mellitus (DM) seen in a significant number of patients, which is often ignored and is also least frequently diagnosed. It can be diagnosed by performing five standard non-invasive bedside autonomic function tests based on Cardiovascular reflexes, which are quite cumbersome. Studies have revealed an increase in mortality in the diabetic patients with CAN due to silent cardiac ischemia, sudden cardiac death, arrhythmias. The precursor of diabetic cardiomyopathy is Left ventricular diastolic dysfunction (LVDD). In the present study we are studying the association between LVDD and CAN, in order to identify high mortality risk patients by performing 2D Echo and looking at LVDD instead of performing the cumbersome bedside cardiovascular autonomic function tests. To study the association between LVDD and CAN in patients with Type 2 DM. This study is a cross-sectional observational study with a sample size of 100. Both outpatients and inpatients between 35 y and 65 y of age with Type 2 DM coming to Department of General Medicine, KIMS hospital, Bangalore were studied from November 2011 to October 2013.Patients with macrovascular complications, Hypertension, congenital & acquired heart diseases etc. were excluded from the study. The standard five autonomic function tests based on cardiovascular reflexes and 2D Echo were performed. Individual scores for each of the five tests were added to produce Ewing's score. Ewing's score of >2.5 is positive for CAN. Chi-square/ Fisher Exact test has been. There was a significant association between individual non-invasive bedside tests of Ewing's score and LVDD. Significant association was also seen between LVDD and positive Ewing's score. Positive Ewing's score is strongly associated with LVDD in patients with Type 2 DM in this study .This suggests that patients with LVDD have CAN and hence, are at increased risk of sudden cardiac death. As bedside tests are cumbersome, patients with LVDD on 2D Echo can be concluded to have CAN.