Related Experiment Video
Updated: Jan 24, 2026

Patient Directed Recording of a Bipolar Three-Lead Electrocardiogram using a Smartwatch with ECG Function
Published on: December 11, 2019
Higher Prevalence of Abnormal Electrocardigrams (ECG) in African Americans Undergoing Screening ECG and
Mohammad Reza Movahed1,2, Sudhakar Sattur1, Sharon Bates3
1From the Sarver Heart Center, University of Arizona, Tucson, AZ.
Background:
African American (AA) has higher prevalence of abnormal electrocardigrams (ECG) in general population. However, the degree of these abnormalities in a healthy population undergoing screening echocardiography is not known. The goal of this study was to evaluate the prevalence of ECG abnormalities reported during screening echocardiography based on race.
Method:
The Anthony Bates Foundation has been performing screening across the United States for the prevention of sudden death since 2001. We evaluated a total of 633 participants with documented race and ECG for the presence of any abnormalities.
Results:
The age of the study population ranged between 6 and 75 years old. The prevalence of abnormal ECG in AA participant was 20.7% (12/58) versus 6.6% (38/578) in other races [odds ratio (OR), 3.70; confidence interval (CI), 1.8-7.58; P < 0.001]. Using multivariate analysis adjusting for age, sex, body mass index, left ventricular hypertrophy, and hypertension (systolic blood pressure >140 and diastolic blood pressure of >90), AA race remained independently associated with abnormal ECG (OR, 2.58; CI, 1.12-5.97; P = 0.02). Limiting our study only to teenagers (age, 13-19 years), AA race remained significantly associated with higher prevalence of ECG abnormalities [23.1% (12/58) of teenage AA had abnormal ECG vs. 7.5% (24/321) of other teenage races; OR, 3.71; CI, 1.36-10.11; P = 0.006]. After excluding benign ECG abnormalities such as sinus bradycardia and early repolarization, AA race remained significantly associated with higher prevalence of abnormal ECG (16.7% vs. 7.3%; OR, 2.52; CI, 0.998-6.39; P = 0.054).
Conclusions:
The prevalence of abnormal ECG is higher in AA race independent of echocardiographic abnormalities or demographics. However, some of these abnormalities appear to be related to sinus bradycardia and early repolarization.
Related Concept Videos
ECG Interpretation of Rhythms
Components of the Electrocardiogram
The primary components of a normal ECG waveform in Normal sinus rhythm(NSR) include the P wave, PR interval, QRS complex, ST segment, T wave, and occasionally a U wave.
ECG waveforms are divided by vertical and horizontal lines at standard intervals.
The horizontal axis measures time and rate, and the vertical axis measures amplitude or voltage....
Correlation between ECG and Cardiac Cycle
A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before...
ECG Interpretation of Arrhythmias I: Sinus Arrhythmias
Types of Arrhythmias
Sinus Node Arrhythmias
Sinus Bradycardia: Originating from the sinoatrial (SA) node, sinus bradycardia involves slower impulses, resulting in a heart rate of less than 60 beats per minute (bpm). Causes include sleep, vagal stimulation, beta-blockers, hypothyroidism,...
ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias
Prevalence and Incidence
Prevalence indicates the proportion of individuals in a population who have a specific disease or health...
Electrocardiogram
Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and...

