The Electrocardiogram in Some Indian Population Groups.

SEVERAL epidemiologic studies of cardio-vascular diseases are now being under-taken with a view to assessing the relative incidence of the different types of heart disease .1-4 The methods of assessment of electro-cardiograms in such studies have been the subject of debate. The definition of a normal electrocardiogram has become difficult, as with increasing numbers of subjects studied the range of normality is widened. The Research Committee of the International Society of Cardiology,5 the Minnesota Code,6 Higgins' modificationj7 and the W.H.O. Expert Committee 8 have all adopted certain criteria for the interpretation of the electrocardiogram. Although these methods are somewhat different and although none has found universal acceptance, there is general agreement on the need to report the so-called "abnormal-ities" in the different population groups as such, rather than to interpret them. In this paper the recommendations of the Research Committee of th1 International Society of Cardiology,5 and of the W.H.O. Expert Committee 8 have been largely followed and the features are recorded rather than interpreted. Material and Methods The electrocardiograms of 941 subjects belonging to some South-Indian population groups, civil and military, were studied. The dietary habits, total serum cholesterol and phospholipid levels, blood pressure, and coagulation times of these subjects have been reported earlier.9 Table 1 shows the age, income, and occupation of these subjects who were all healthy male adults without any clinical evidence of heart disease. The civilian subjects were drawn from the industrial and nonindustrial population belonging to the Nilgiris district (Madras State), Trivandrum (Kerala State), and Hyderabad (Andhra Pra-desh). Officers of the defence forces undergoing the staff course at the Defence Services Staff College at Wellington and sepoys and other ranks stationed in the Nilgiris constituted the army personnel. No selection of subjects was made in any of these groups. All the 121 army officers in the staff college during the year 1958 were studied. The subjects representing industrial labor were from the Cordite factory in the Nilgiris district and foimed 16 per cent of the total factory strength. Nonindustrial subjects were members of the staff of thebad, and professional people and businessmen in Coonoor. The subjects at Trivandrum were drawn from the secretarial staff, Medical College and Hospital staff, and from the city and surrounding areas. In the early stages of this study subjects over 20 years of age were included but later only subjects beyond 30 years were studied. A subject was designated …