Ethnic differences in left ventricular size and the prevalence of left ventricular hypertrophy among hypertensive patients vary with electrocardiographic criteria.

The objective of this study was to investigate differences in electrocardiographic (ECG) parameters and the prevalence of left ventricular hypertrophy (LVH) by various ECG criteria between different ethnic groups in west Birmingham, United Kingdom. In all, 380 consecutive patients, mean age 63 (7.8) years, 75 (20%) female patients assessed for inclusion in hypertension trials in a city centre teaching hospital were studied: 303 (80%) were Caucasian, 43 (11.4%) Afro-Caribbean and 32 (8.5%) South Asian. LVH was assessed using seven different criteria, with adjustment for age and body mass index (BMI). The performance of the various criteria were compared between the three ethnic groups. There were significant differences in the R-wave voltage in lead aVL, the Sokolow-Lyon voltage and in criteria based on limb lead voltages alone between the three ethnic groups. Highest ECG voltages were seen in Afro-Caribbeans, and this translated into a significantly higher prevalence of LVH when assessed by the R-wave in aVL and the Sokolow-Lyon criteria. There were no significant differences between Caucasians and South Asians. These differences were abolished after adjustment for age and BMI. There was no difference in the Cornell voltage or its derivatives in men between the three ethnic groups. In conclusion, apparent differences in electrocardiographic voltage and the prevalence of LVH between ethnic groups are dependent upon the criteria chosen and may simply be secondary to differences in BMI. Unlike Afro-Caribbean patients, South Asians do not demonstrate significant differences in ECG voltage compared with Caucasians.