In a large recent study the corrected QT duration (QT,) was reported to be
longer in Caucasians than in African-Americans. Because a longer QT interva
l is associated with an increased risk of cardiovascular mortality, we meas
ured raw QT intervals within strata of heart rate as well as QT, in African
-American and Caucasian persons without cardiac disease, but found only sma
ll differences between races.