Can an electrocardiogram (ECG) be inaccurate?

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Last updated: May 21, 2025View editorial policy

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From the Guidelines

Yes, an ECG can be wrong, with major interpretation errors occurring in 4% to 33% of cases, although adverse patient outcomes resulting from these errors are rare, typically occurring in less than 1% of interpretations 1.

Factors Affecting ECG Accuracy

Several factors can contribute to ECG inaccuracy, including:

  • Improper electrode placement
  • Patient movement during the test
  • Electrical interference
  • Technical issues with the machine
  • Certain physical conditions like obesity or lung disease
  • Intermittent heart problems that might not be captured during the brief recording period of a standard ECG

Clinical Decision Making

Given the potential for errors, computer analyses of ECGs should be considered a helpful adjunct to, but not a substitute for, physician interpretation in clinical decision making 1. Physicians must have sufficient knowledge to understand and accurately recognize the basic pathophysiology of electrocardiographic abnormalities.

Diagnostic Process

Doctors often use ECGs as just one tool in their diagnostic process, combining the results with:

  • Patient symptoms
  • Medical history
  • Physical examination findings
  • Sometimes additional cardiac tests like echocardiograms or stress tests If there's uncertainty about an ECG result, your doctor might recommend repeating the test or pursuing further cardiac evaluation to ensure an accurate diagnosis 1.

From the Research

ECG Interpretation Errors

  • ECGs can be wrong due to various reasons, including misinterpretation by artificial intelligence (AI) or human error 2, 3, 4.
  • A study found that 2.0% of ECGs were misinterpreted, with wrongly diagnosed atrial fibrillation being the most common 2.
  • Misinterpretation of ECGs can lead to inappropriate medical therapies, such as the use of antiarrhythmic drugs, beta-blockers, and anticoagulation, as well as increased resource utilization 2.

Common Errors in ECG Recording

  • Inaccurate lead placement, inappropriate serial comparisons, lead wire reversals, and excessively noisy signals can lead to errors in ECG recording 4.
  • Practical strategies can be implemented to prevent errors and improve the quality and utility of ECGs, such as careful examination of AI-interpreted ECGs 2, 4.

Accuracy of ECG Interpretation

  • The accuracy of ECG interpretation by cardiologists can be affected by incorrect computer analysis, with cardiologists as primary readers being more accurate than overreading cardiologists 5.
  • Knowledge of an individual patient's clinical information can result in a more critical rhythm assessment and higher accuracy of rhythm interpretation 5.

Clinical Implications

  • Misinterpretation of ECGs can have significant clinical implications, including inappropriate treatment and increased resource utilization 2, 3.
  • Clinicians should be aware of the potential for ECG interpretation errors and take steps to minimize them, such as careful examination of ECGs and consideration of clinical context 2, 5.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Erroneous electrocardiographic interpretations and its clinical implications.

Journal of cardiovascular electrophysiology, 2023

Research

Misleading ECG recordings.

Singapore medical journal, 2011

Research

Pitfalls and artifacts in electrocardiography.

Cardiology clinics, 2006

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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