Distinctive ECG patterns in healthy black adults.

Six ECG patterns are found more frequently in healthy black adults than in whites. These patterns are presumably benign, but also may resemble those of malignant disease. 1) Healthy black adults show higher QRS voltage, and more often meet ECG criteria for left ventricular hypertrophy (LVH). Associated repolarization abnormalities can produce ST segment elevation (STE) that resembles ST elevation MI (STEMI). 2) The pattern of benign anterior STE, seen often in males, is more common in black subjects. Similar to LVH, this pattern may falsely suggest STEMI. 3) Both early repolarization (ER) and benign inferolateral STE are more common in black patients. Although they may convey a higher risk of fatal arrhythmias or cardiac death in white populations, it does not appear that black subjects with these patterns show a similar risk. 4) The persistent juvenile T wave inversion pattern shows asymmetric T wave inversion (TWI) in V1-V4, without ST segment deviations. It is most common in black females, and is considered benign. However, this pattern can also resemble the anterior TWI of arrhythmogenic right ventricular cardiomyopathy (ARVC). 5) A pattern of anterior TWI with associated J point elevation is a common finding in the black population, especially athletes. It could suggest hypertrophic cardiomyopathy, but can be presumed to be a benign finding in black athletes, when TWI is limited to V1-V4 and preceded by J point elevation. 6) TWI in the lateral precordial leads, usually associated with end-QRS slurring or notches is seen much more often in apparently healthy black subjects than white subjects. Unlike the anterior TWI pattern, however, it cannot be presumed benign. In conclusion, awareness of these ECG patterns may help to avoid unnecessary diagnostic or therapeutic interventions, but also encourage appropriate investigations.