Lower prevalence of intraventricular block in African-American patients compared with Caucasian patients: an electrocardiographic study II.

Background: Electrocardiographic (ECG) differences occur between African-American and white persons.

Methods: Intraventricular conduction abnormalities of ECGs of 2,123 African-American and white hospital patients ages 20-99 years were studied in a consecutive manner.

Results: Intraventricular conduction abnormalities develop later in life and are less common in African-American patients, compared with white patients. The prevalence of conduction abnormalities increases with advancing age in both races. Left- and right ventricular conduction abnormalities begin to rise at age 50 for white patients but begin to rise at age 70 for African-American patients. The prevalence of left ventricular conduction abnormalities peaks in the ninth decade of life in both races but declines in both races in the tenth decade of life. The prevalence of right ventricular conduction abnormalities gradually increases and peaks in the tenth decade of life in both races.

Conclusions: The prevalence of intraventricular block is significantly less in African-American patients, compared with white patients--occurring in 8.6% of African-American patients and in 15.2% of white patients. The prevalence of intraventricular block is lowest in African-American women at 6.5% and highest in white men at 16.8%.