Sensitivity and specificity of the electrocardiogram in predicting the presence of increased left ventricular mass index on the echocardiogram in Afro-Caribbean hypertensive patients.

Abstract

Cardiovascular disease is emerging as the leading cause of death in the Caribbean region with hypertension along with diabetes mellitus representing the major causes. Left ventricular hypertrophy associated with hypertension results in a two to fourfold increase in cardiac morbidity and mortality. One hundred and eleven patients, 67% female, mean age 46 years with a mean of seven years since diagnosis, had resting blood pressure, electrocardiogram and sector-focused M-mode echocardiogram performed The electrocardiograms were analyzed for left ventricular hypertrophy using Sokolow-Lyon, Cornell, Romhilts-Estes, 12 lead sum, QRS duration, 12 lead-QRS product and left ventricular strain pattern. The echocardiograms were analyzed for increased left ventricular mass using the formula of Devereux and Reichek indexed to height. The mean systolic blood pressure was 156 mmHg, mean diastolic blood pressure was 97 mmHg on treatment. At least one electrocardiographic criterion for left ventricular hypertrophy was seen in 47/111 (42%) patients and increased left ventricular mass index was seen in 55/111 (50%) patients. Sensitivity, specificity and positive predictive value of the electrocardiogram in predicting increased left ventricular mass index was best for Sokolow-Lyon (31%, 86%, 76%), Cornell (23%, 96%, 88%) and 12 lead-QRS product (30%, 86%, 72%). Sensitivity ranged from 3 to 31%, specificity from 80 to 96% and positive predictive value from 40 to 88%. The electrocardiogram is insensitive in detecting increased echocardiographic left ventricular mass index, as in patients from developed countries, and is less specific for the finding as in African Americans.