What diagnostic tests are indicated for patients with electrical injury?

Diagnostic Tests for Electrical Injury

The recommended diagnostic tests for patients with electrical injury include 12-lead ECG, cardiac biomarkers, echocardiography, and additional targeted testing based on injury severity, with ECG monitoring generally indicated only for those with abnormal initial ECG, loss of consciousness, or documented arrhythmia. 1

Initial Assessment

• A standard 12-lead ECG should be performed on all patients with electrical injury to detect potential cardiac abnormalities 1
• Cardiac biomarkers including troponin and CK/CK-MB should be measured to assess for myocardial injury 2, 3
• Complete blood count, serum electrolytes, renal function tests (BUN, creatinine), and urinalysis should be performed to evaluate for systemic effects 2
• Creatine kinase (CK) and myoglobin levels should be monitored, with peak levels typically occurring at post-injury day 1 (myoglobin) and day 2 (CK) 4

Cardiac Evaluation

• Echocardiography is recommended for all patients with suspected ventricular arrhythmias or structural heart disease following electrical injury 1
• Continuous ECG monitoring is indicated for patients with:
  • Abnormal initial ECG 5
  • History of loss of consciousness during the electrical injury 5
  • Documented arrhythmia in the field 5
  • High-voltage injury (>1000V) with cardiac symptoms 4, 3

Advanced Cardiac Testing

• Exercise testing with imaging (echocardiography or nuclear perfusion) is recommended for patients with suspected silent ischemia who have intermediate probability of coronary artery disease 1
• Pharmacological stress testing with imaging should be used for patients unable to perform exercise testing 1
• Coronary angiography should be considered in patients with life-threatening ventricular arrhythmias or survivors of sudden cardiac arrest with intermediate or greater probability of coronary artery disease 1

Electrophysiological Testing

• Electrophysiological (EP) testing is recommended for diagnostic evaluation of patients with symptoms suggestive of ventricular tachyarrhythmias including palpitations, presyncope, and syncope following electrical injury 1
• EP testing can be useful in patients with syncope when bradyarrhythmias or tachyarrhythmias are suspected and non-invasive studies are inconclusive 1

Neurological Assessment

• Neuropsychiatric testing should be considered for patients with cognitive complaints or symptoms of neurological injury 6
• Signal-averaged ECG may be considered for suspected arrhythmogenic cardiomyopathy 7

Monitoring Recommendations

• Routine cardiac monitoring beyond 24 hours post-injury does not appear necessary for patients with normal initial ECG and no history of arrhythmia or loss of consciousness 3, 5
• For high-voltage injuries (>1000V), more intensive monitoring and evaluation is warranted due to higher risk of cardiac arrest, loss of consciousness, and other complications 6, 4

Important Considerations

• High-voltage injuries (>1000V) are associated with greater morbidity and mortality compared to low-voltage injuries, requiring more extensive evaluation 4
• Cardiac arrhythmias typically occur at the time of injury or shortly thereafter, with late-onset malignant arrhythmias being rare 3, 8
• Admission CK and myoglobin levels correlate with injury severity, need for surgical interventions, and risk of complications including renal failure 4
• The risk of developing chronic cardiac disease after electrical injury is not well established, and patients with significant cardiac involvement should be followed for at least 12 months 8