Should I order an electrocardiogram (EKG) for a patient presenting with altered mental status or psychosis, including symptoms like hearing voices or hallucinations?

EKG in the Workup of Altered Mental Status or Psychosis with Hallucinations

An electrocardiogram (EKG) should be included as part of the standard workup for patients presenting with altered mental status or psychosis with hallucinations, as it can identify potentially life-threatening medical causes that require immediate intervention. 1

Rationale for EKG in Altered Mental Status Workup

Altered mental status (AMS) is not a diagnosis but rather a symptom complex that can be caused by numerous underlying medical conditions. The 2024 ACR Appropriateness Criteria highlights that mortality in patients with AMS is approximately 8.1% and significantly higher in elderly patients 1. Importantly, the guidelines specifically mention that "the complete evaluation for underlying causes, such as chest radiography to assess for pneumonia, electrocardiogram to assess for myocardial ischemia, electroencephalography for suspected convulsive or nonconvulsive seizure, and lumbar puncture to assess for central nervous system infection" is essential in the workup of these patients 1.

Importance of EKG in Psychosis/Hallucinations Workup

For patients presenting with psychosis or hallucinations:

1. Secondary causes must be ruled out before assuming primary psychiatric etiology. Medical conditions that may present with psychotic symptoms include:

   • Endocrine disorders
   • Cardiovascular conditions (including myocardial ischemia)
   • Neurological disorders
   • Metabolic derangements
   • Drug-related intoxication or withdrawal 1

2. Cardiac abnormalities may be present at higher rates in patients with severe mental illness, even at younger ages. A study found that 21% of patients admitted to an acute psychiatric unit had clinically relevant ECG abnormalities 2.

3. Case evidence supports EKG utility - a case report described a 38-year-old patient with altered mental status where an EKG provided critical diagnostic information, revealing bradycardia that led to the discovery of hypothermia as the underlying cause 3.

Diagnostic Algorithm for AMS/Psychosis Workup

1. Initial assessment:

   • Vital signs (including temperature)
   • Focused neurological examination
   • EKG to assess for:
     • Myocardial ischemia
     • Arrhythmias
     • Electrolyte abnormalities (e.g., hyperkalemia)
     • QT prolongation (which may be medication-induced)

2. Laboratory studies:

   • Complete blood count
   • Comprehensive metabolic panel
   • Toxicology screen
   • Thyroid function tests

3. Neuroimaging when indicated:

   • Head CT or MRI (particularly with focal neurologic deficits)

4. Additional testing based on clinical suspicion:

   • Lumbar puncture
   • EEG (especially with fluctuating mental status)

Special Considerations for Auditory Hallucinations

Auditory hallucinations are not always indicative of a psychotic disorder 4, 5. They may result from:

• Hearing loss (especially in elderly)
• Temporal lobe epilepsy
• Post-traumatic stress disorder
• Sleep disorders
• Borderline personality disorder

An EKG can help rule out medical causes that might contribute to these symptoms, particularly in patients with no prior psychiatric history or with atypical presentations 5.

Common Pitfalls to Avoid

1. Premature psychiatric diagnosis: Assuming psychosis is primary without ruling out medical causes can lead to missed diagnoses of potentially life-threatening conditions.

2. Overlooking cardiac issues: Patients with severe mental illness have higher rates of cardiovascular disease that may be undiagnosed 2.

3. Age bias: Assuming younger patients with psychiatric symptoms don't need medical workup. Even young patients with psychosis can have significant ECG abnormalities 2.

4. Medication effects: Many psychiatric medications affect cardiac conduction, making baseline and follow-up EKGs essential.

5. Incomplete workup: The 2024 guidelines emphasize that delirium is a medical emergency with mortality twice as high if the diagnosis is missed 1.

By including an EKG in the standard workup for altered mental status or psychosis with hallucinations, clinicians can identify potentially life-threatening medical causes requiring immediate intervention, while avoiding inappropriate psychiatric diagnoses and treatments for what may be medical conditions.