A comparison of T-wave inversion, S-T elevation, and RS amplitudes in precordial leads of Africans and Indians in Guyana

Abstract

ECG precordial leads of 830 Guyanese men and women of African and Indian origin, aged 35 to 54 years, were compared. The prevalence of nonupright T waves in right precordial leads (V 1 to V 3) were similar in the two ethnic groups. T-wave inversion in V 1, V 2, and V 3 was present in 46.4 per cent, 3.5 per cent, and 2.4 per cent of women, respectively, compared with 9.6 per cent in V 1 and no inversion in V 2 and V 3 in men. S-T elevation occurring in any of the precordial leads was present in 2.1 per cent of African women, 0.9 per cent of Indian women, 18.1 per cent of African men, and 13.6 per cent of Indian men. Neither T-wave inversion in right precordial leads nor S-T elevation were associated with detectable clinical abnormality, hypertension, obesity, or raised blood cholesterol levels and both appeared to be normal variants. S-T elevation was associated with large QRS complexes. Mean amplitudes of S waves in V 1 and R waves in V 5 and V 6 were significantly greater in men than in women and in Africans than Indians. These differences could only be partially explained by variations in age, blood pressure, obesity, or cardiothoracic ratios. Possible ethnic and sex differences in the prevalence of T-wave inversion in right precordial leads, S-T elevation, and high amplitude QRS complexes can be of clinical and epidemiological importance.