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v1.0.0
ICD-10 Guide
DiagnosesAbnormal Electrocardiogram

Abnormal Electrocardiogram

ICD-10 Coding for Abnormal Electrocardiogram(R94.31, I48.91)

PRIMARY SPECIALTYEmergency Medicine
COMPLEXITYHigh
LAST UPDATED09/15/2025
Sam Tuffun, PT, DPT
Physical Therapist | Medical Coding & Billing Contributor

Diagnosis Overview

What is Abnormal Electrocardiogram?
Essential facts and insights about Abnormal Electrocardiogram

Key Clinical Considerations:

  • Presence of abnormal rhythms or patterns in the ECG
  • Signs of heart disease or damage visible on the ECG
  • Symptoms like chest pain, shortness of breath, or fainting that correlate with ECG abnormalities

Clinical Information

Clinical Criteria & Documentation Requirements

  • Detailed description of the abnormal ECG findings
  • Record of patient's symptoms and physical examination
  • Documentation of any underlying heart conditions

Coding Guidelines

Usage Guidelines & Examples

  • R94.31 is used for abnormal electrocardiogram [ECG] [EKG] without diagnosis, while I48.91 is used for unspecified atrial fibrillation and atrial flutter
  • R94.31 is a nonspecific code and should be used only when a more specific code is not available

Code Exclusions

Important Exclusions

  • Conditions where the ECG is normal despite symptoms (these require different codes)
  • Specific heart rhythm disorders that have their own codes

Related ICD-10 Codes

Primary Codes
R94.31
Abnormal electrocardiogram [ECG] [EKG]
I48.91
Unspecified atrial fibrillation and atrial flutter
Ancillary Codes
R07.9
Differential Codes
I48.91
I48.91
when atrial fibrillation is specifically documented.
I48.92
I48.92
when atrial flutter is documented instead of fibrillation.

Related CPT Codes

CPT codes will be available in a future update.

Specialty Focus

Primary Specialty

Emergency Medicine

Specialty Applications

  • Patients presenting with symptoms of heart disease
  • Patients with known heart conditions undergoing routine monitoring
  • Emergency situations where heart disease is suspected

Coding Complexity

High Complexity

This diagnosis requires careful attention to:

  • Comprehensive clinical documentation
  • Accurate code selection based on clinical criteria
  • Proper exclusion considerations
  • Specialty-specific coding guidelines

Documentation

Documentation Templates

Template 1

Patient presented with [symptoms]. ECG showed [specific abnormalities].

Template 2

Abnormal ECG findings include [specific findings]. Patient's symptoms include [symptoms].

Billing Information

Billing Considerations

  • Ensure proper documentation for billing
  • Verify code specificity requirements
  • Check for any additional codes needed
  • Review payer-specific guidelines

Common Issues

  • Insufficient clinical documentation
  • Incorrect code selection
  • Missing supporting diagnoses
  • Timing and frequency documentation

Frequently Asked Questions

What constitutes an 'abnormal' ECG?

Any rhythm or pattern on the ECG that deviates from the normal sinus rhythm can be considered abnormal.

When should this code be used?

This code should be used when an abnormal ECG is found, but no specific diagnosis has been made yet.