Clinical Features of Cardiac Disorders in Diabetes Mellitus

Diabetics have greater prevalence of heart disease such as ischaemic heart disease, hypertensive heart disease, cardiomyopathy and congestive heart failure [1, 2, 3]. The diabetic state shows many metabolic abnormalities which adversely influence atherosclerosis causing coronary artery disease and peripheral vascular disease. The overall prevalence of CAD as assessed by various tests including coronary angiography which is around 55% amongst diabetics compared with 24% in general populations of comparable age. In our study of 200 cases of NIDDM subjected to treadmill exercise test, we found stress test positive for ischaemia in 50% of cases. CAD is not only more prevalent but is more severe in diabetics than in non-diabetics. On coronary angiography, diabetics often have multivessel CAD when compared to age and sex matched non-diabetics [4]. As regards clinical presentation of coronary artery disease in diabetics, it may present as stable angina, unstable angina or acute myocardial infarction. But the clinical features and course of heart disease in diabetes mellitus have some peculiarities. For example, chest pain may be absent or atypical in character and location in a patient presenting with angina or myocardial infarction. Patient may present with breathlessness as angina equivalent or acute dyspnoea due to left ventricular failure in acute myocardial infarction. In other cases of acute myocardial infarction, patient may present with arrhythmias or hypotension without chest pain [5]. Ischaemic heart disease in diabetics occurs at the same age as in non-diabetics. ECG abnormalities are as frequent in diabetic females as in males, unlike in non-diabetics. The occurance of CAD is not related to the duration and severity of diabetes mellitus. Diabetics have a greater prevalence of painless sudden death particularly during sleep [4, 5, 6].