title: Comparison of the prevalence of first-degree atrioventricular block in African-American and in Caucasian patients: an electrocardiographic study III.
abstract: BACKGROUND
  Electrocardiographic (ECG) differences occur between African-American and Caucasian patients.
  
  
  METHODS
  The study includes ECGs of 2,123 patients, ages 20-99 years attending an urban hospital.
  
  
  RESULTS
  First-degree atrioventricular (AV) block was more prevalent in African-American patients compared with Caucasian patients in all age groups of the study except for those patients in the eighth decade of life. The prevalence of first-degree AV block began to increase at age 50 years in both ethnic groups and gradually increased with advancing age, peaking in African-American patients in the 10th decade of life, and in Caucasian patients in the ninth decade of life. The continuing increase in first-degree AV block in African-American patients in the 10th decade of life suggests increasing impairment but greater durability of the AV conduction system in African-American compared with Caucasian patients. The dramatic decline of the prevalence of first-degree AV block in Caucasian patients in the 10th decade of life suggests more frequent failure of the AV conduction system in this group of patients at ages 90-99 years, compared with African-American patients in the same age group. In population-based surveys, first-degree AV block was more prevalent in African-American subjects compared with Caucasian subjects.
authors.affiliation: Department of Internal Medicine, Carter Smith, Sr. Electrocardiographic Laboratory, Piedmont Hospital, Atlanta, GA, USA.
authors.forename: Charles B
authors.initials: CB
authors.lastname: Upshaw
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044383:Black People / Q000706:statistics & numerical data; D004562:Electrocardiography; D005260:Female; D005845:Georgia / Q000453:epidemiology; D006327:Heart Block / Q000453:epidemiology / Q000208:ethnology*; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D015995:Prevalence; D044465:White People / Q000706:statistics & numerical data; D001741:Black or African American