What should I do for a patient with tachycardia and severe untreated anxiety?

Management of Acute Tachycardia with Severe Untreated Anxiety

Obtain a 12-lead ECG immediately to document the rhythm and rule out a primary cardiac arrhythmia, as anxiety and supraventricular tachycardia (SVT) present with nearly identical symptoms and distinguishing between them is critical for appropriate management. 1, 2

Immediate Assessment

Your first priority is determining whether this represents a primary cardiac arrhythmia versus anxiety-induced sinus tachycardia:

• Check vital signs and attach cardiac monitoring to assess current heart rate and rhythm 3
• Obtain a 12-lead ECG now - this is essential even though the episode has resolved, as it may show pre-excitation (delta waves suggesting WPW syndrome) or other abnormalities that indicate the type of tachycardia 1, 2
• Assess for hemodynamic stability - check for chest pain, shortness of breath, hypotension, or altered mental status 3

Critical Diagnostic Consideration

The 2-hour duration strongly suggests a true paroxysmal supraventricular tachycardia (PSVT) rather than anxiety-induced sinus tachycardia alone. 1 Here's why this distinction matters:

• PSVT is frequently misdiagnosed as panic disorder because symptoms are nearly identical: palpitations, chest discomfort, dyspnea, and lightheadedness 4, 5
• Sinus tachycardia from anxiety typically has gradual onset and termination, whereas PSVT has abrupt onset and termination 1
• Episodes lasting 2 hours are more consistent with PSVT (specifically AVNRT or AVRT) than simple anxiety 1
• Studies show that 15% of patients undergoing successful PSVT ablation were being treated with psychiatric medications, and catheter ablation reduced their need for these medications 4

Immediate Workup Required

Since the episode has resolved, proceed with the following evaluation:

Essential Testing

• 12-lead ECG (if not already done) - look specifically for:

  • Pre-excitation pattern (short PR interval, delta wave) suggesting WPW syndrome 1, 2
  • Any baseline abnormalities 2

• Basic labs to exclude reversible causes:

  • Thyroid function (TSH) - hyperthyroidism causes tachycardia 1
  • Complete blood count - anemia can cause compensatory tachycardia 1
  • Basic metabolic panel - electrolyte abnormalities 2

Additional Cardiac Evaluation

• Echocardiogram to assess for structural heart disease 1, 2
• Ambulatory monitoring (Holter monitor or event recorder) to capture future episodes, as recurrent paroxysmal palpitations require rhythm documentation 1, 6
• Exercise stress test if episodes are exercise-related 1

When to Refer to Cardiology

Refer to a cardiac electrophysiologist for:

• Any documented wide-complex tachycardia (requires urgent consultation even if self-terminated) 1, 6
• Presence of pre-excitation on baseline ECG with history of paroxysmal regular palpitations - this is sufficient for presumptive diagnosis of AVRT and warrants referral without needing to capture the arrhythmia 1
• Recurrent episodes of regular, paroxysmal palpitations with abrupt onset/termination - these patients may benefit from catheter ablation 1
• Disabling symptoms or drug resistance/intolerance 1

Management of Anxiety Component

While evaluating for cardiac causes:

• Do not dismiss the anxiety as the sole cause until cardiac evaluation is complete - the anxiety may actually be secondary to undiagnosed PSVT 4, 5
• If cardiac workup is negative, then address anxiety with appropriate psychiatric referral and treatment 2
• If PSVT is confirmed, catheter ablation may reduce or eliminate need for anxiety medications 4

Critical Pitfalls to Avoid

• Do not assume this is "just anxiety" without proper cardiac evaluation - PSVT and panic attacks have overlapping symptoms, and misdiagnosis leads to years of inappropriate treatment 4, 5
• Do not prescribe benzodiazepines (like lorazepam) as first-line treatment without ruling out cardiac causes - these mask symptoms without treating underlying arrhythmia 7
• Do not use AV nodal blocking agents (beta-blockers, calcium channel blockers) if pre-excitation is present on ECG, as this can be dangerous in atrial fibrillation with WPW 3

Patient Education and Follow-up

Instruct the patient to:

• Seek immediate emergency care if tachycardia recurs with:

  • Heart rate persistently >150 bpm 6, 3
  • Syncope or near-syncope 2
  • Severe chest pain or shortness of breath 2

• Schedule cardiology follow-up within 1-2 weeks for review of test results and further management planning 2

Bottom Line

This 2-hour episode of "racing heartbeat" in a young patient with anxiety requires full cardiac evaluation before attributing symptoms to anxiety alone. The duration and pattern suggest possible PSVT, which is commonly misdiagnosed as panic disorder and can be definitively treated with catheter ablation. 1, 4, 5