What are the initial recommendations for treating panic-driven tachycardia, specifically regarding vagal maneuvers?

Vagal Maneuvers for Panic-Driven Tachycardia

Critical First Consideration

Vagal maneuvers are only effective for supraventricular tachycardias (SVT) that involve the AV node as part of a reentrant circuit—they will NOT work for sinus tachycardia caused by panic or anxiety. 1

Understanding the Clinical Context

Panic-driven tachycardia is typically sinus tachycardia, which represents a normal physiologic response to anxiety and catecholamine release. This is fundamentally different from SVT:

• Sinus tachycardia has a gradual onset and termination, with rates typically 100-150 bpm, and P waves precede each QRS complex 2
• SVT (AVNRT/AVRT) has abrupt onset and termination, often with rates 150-250 bpm, and may have absent or retrograde P waves 2, 3
• Vagal maneuvers work by increasing vagal tone to slow AV nodal conduction, interrupting reentrant circuits 1
• Since sinus tachycardia does not involve a reentrant circuit through the AV node, vagal maneuvers will not terminate it 1

If This Is True SVT (Not Panic-Driven Sinus Tachycardia)

First-Line Treatment Algorithm

The modified Valsalva maneuver is the most effective vagal technique and should be attempted first in hemodynamically stable patients. 2, 1, 4

Step 1: Modified Valsalva Maneuver

• Position patient supine 2
• Have patient bear down against a closed glottis for 10-30 seconds, generating at least 30-40 mm Hg intrathoracic pressure 2
• The modified technique (with postural modification) achieves conversion rates 5.47 times higher than carotid sinus massage 4
• Success rate: terminates up to 25-27.7% of PSVTs 2

Step 2: Alternative Vagal Maneuvers (if Valsalva fails)

• Ice-cold wet towel to face or facial immersion in 10°C water (diving reflex) 2
• Carotid sinus massage: Only after confirming absence of carotid bruit by auscultation, apply steady pressure over right or left carotid sinus for 5-10 seconds 2, 1
• Switching between techniques increases overall success to 27.7% 2

Step 3: Pharmacologic Therapy (if vagal maneuvers fail)

• Adenosine 6 mg IV rapid push through large vein followed by 20 mL saline flush 2
• If no conversion in 1-2 minutes, give 12 mg rapid IV push 2
• Adenosine terminates AVNRT in approximately 95% of patients 2
• Have defibrillator available due to risk of atrial fibrillation with rapid ventricular rates in WPW 2

Step 4: Cardioversion (if medications fail or patient unstable)

• Synchronized cardioversion for hemodynamically unstable patients when adenosine and vagal maneuvers fail 2, 1
• Also indicated for stable patients when pharmacologic therapy fails or is contraindicated 2

If This Is Panic-Driven Sinus Tachycardia

Vagal maneuvers will not terminate sinus tachycardia—treatment should focus on addressing the underlying panic/anxiety:

• Reassurance and calming techniques
• Anxiolytic medications if severe (benzodiazepines)
• Beta-blockers for symptomatic rate control if needed
• Treatment of the underlying panic disorder

Critical Pitfalls to Avoid

• Do not assume all tachycardia is SVT—obtain ECG to differentiate sinus tachycardia from SVT before attempting vagal maneuvers 3
• Do not perform carotid massage without first auscultating for bruits—risk of stroke 2, 1
• Do not use eyeball pressure—this technique is dangerous and abandoned 2
• Do not delay cardioversion in unstable patients attempting multiple vagal maneuvers 2, 1
• Diagnosis of SVT is often delayed due to misdiagnosis as anxiety or panic disorder—patient history and rhythm documentation are essential 3