Abstract

Introduction: CAN (Cardiovascular Autonomic Neuropathy) causes resting tachycardia, orthostatic hypotension, exercise intolerance and is associated with higher cardiovascular mortality. It is often under diagnosed, very little data is available regarding cardiac autonomic neuropathy in literature so this study was planned to know the prevalence of CAN in T2 DM.

Aim: To study prevalence of cardiac autonomic neuropathy in type 2 diabetic patients.

Methods: Hundred cases of diabetes mellitus (type 2) with no clinical evidence of cardiac disease  were subjected to cardiac autonomic function tests according to Ewing’s criteria which were heart rate variability during deep breathing, Valsalva maneuver ratio, heart rate response on standing and BP response to standing and BP response to sustained handgrip to find the prevalence of CAN. Patients were categorized as with no CAN, early, definite and severe type of CAN depending upon abnormality of one or more tests.

Results: In this study prevalence of CAN was 54% out of which early, definite and severe involvement was found in 16%,14% and  24% respectively. Cardiac autonomic function tests of heart rate variability during deep breathing, Valsalva maneuver ratio, heart rate response on standing and BP response to standing and BP response to sustained handgrip found abnormal response in 38%,22%,34%,14% and 20% respectively.

Conclusion: Prevalence of CAN among diabetics was 54% and parasympathetic cardiac autonomic function tests are more sensitive for the detection of CAN than sympathetic cardiac autonomic function tests. Development of CAN in diabetic patients lead to poor prognosis, increased silent myocardial infarction and sudden cardiac death hence all diabetic patients should  be routinely evaluated for CAN using these feasible bedside tests.

Keywords: Cardiovascular Autonomic Neuropathy (CAN); Cardiac Autonomic function tests; Ewing’s criteria ;T2 Diabetes Mellitus.