Electrocardiographic findings in a middle-aged African population in the Seychelles islands

This study describes major electrocardiogram (ECG) measurements and diagnos es in a population of African individuals; most reference data have been co llected in Caucasian populations and evidence exists for interethnic differ ences in ECG findings. This study was conducted in the Seychelles islands ( Indian Ocean) and included 709 black individuals (343 men and 366 women) ag ed 25 to 64 years randomly selected from the general population. Resting EC G were recorded by using a validated ECG unit equipped with a measurement a nd interpretation software (Cardiovit AT-6, Schiller, Switzerland). The epi demiology of 14 basic ECG measurements, 6 composite criteria for left ventr icular hypertrophy and 19 specific ECG diagnoses including abnormal rhythms , conduction abnormalities, repolarization abnormalities, and myocardial in farction were examined. Substantial gender and age differences were found f or several ECG parameters. Moreover, tracings recorded in African individua ls of the Seychelles differed from those collected similarly in Caucasian p opulations in many respects. For instance, heart rate was approximately 5 b eats per minute lower in the African individuals than in selected Caucasian populations, prevalence of first degree atrio-ventricular block was especi ally high (4.8%), and the average Sokolow-Lyon voltage was markedly higher in African individuals of the Seychelles compared with black and while Amer icans. The integrated interpretation software detected "old myocardial infa rction" in 3.8% of men and 0% of women and "old myocardial infarction possi ble" in 6.1% and 3%, respectively. Cardiac infarction injury scores are als o provided. In conclusion, the study provides reference values for ECG find ings in a specific population of people of African descent and stresses the need to systematically consider gender, age, and ethnicity when interpreti ng ECG tracings in individuals.