Ventricular Tachycardia (VT) - Step-by-Step Management

Step 1: Immediate Assessment - Is There a Pulse?

No Pulse (Pulseless VT) = Cardiac Arrest Protocol

• Start CPR immediately
• Defibrillate (unsynchronized shock) as soon as the defibrillator is available
• Follow ACLS guidelines: epinephrine 1 mg IV every 3-5 min, amiodarone 300 mg IV push (then 150 mg if needed)
• Identify and treat reversible causes (H's and T's)

Pulse Present → Proceed to Step 2

Step 2: Assess Hemodynamic Stability

Step 3: Hemodynamically UNSTABLE VT with Pulse

Synchronized electrical cardioversion immediately. Do not delay for pharmacology.

• If conscious, give sedation/analgesia (procedural sedation) before shocking if clinical status allows - do not delay if severely compromised
• Deliver synchronized DC cardioversion (biphasic 100-200 J; escalate if unsuccessful)
• After restoration of sinus rhythm, proceed to identify and reverse precipitating causes (Step 6)

Step 4: Hemodynamically STABLE VT - Monomorphic

• Obtain a 12-lead ECG
• IV adenosine can be used diagnostically - if it terminates the arrhythmia or reveals an underlying rhythm, it was likely SVT with aberrancy, not VT

Pharmacologic Options (first-line):

• More effective than amiodarone or lidocaine for acute termination
• Dose: 10 mg/kg IV (up to 1000 mg) over 20 minutes
• Caution: vasodilation, hypotension in ~30% of patients
• Contraindicated in end-stage renal disease (metabolite NAPA accumulates → QT prolongation → polymorphic VT)

• Dose: 150 mg IV over 10 minutes, then infusion (1 mg/min x 6 hours, then 0.5 mg/min)
• More effective at slower heart rates; better for preventing recurrence after termination
• Also vasodilator; hypotension in ~30%

• Less effective than amiodarone overall
• More efficacious at faster heart rates; effective for termination but NOT for preventing recurrence
• Useful in acute ischemia setting
• Dose: 50 mg IV bolus, then 2-4 mg/min infusion
• Alternative to amiodarone in patients where amiodarone is contraindicated (e.g., severe iodine allergy)

Key rule: If the patient deteriorates during pharmacologic treatment → immediate synchronized cardioversion.

Special case - Idiopathic VT (no structural heart disease):

• IV beta-blockers - often effective
• Fascicular reentrant VT (idiopathic LV tachycardia): IV verapamil or diltiazem will usually terminate it
• Warning: Calcium channel blockers are absolutely contraindicated for VT in structural heart disease (risk of hemodynamic collapse)

Step 5: Hemodynamically STABLE VT - Polymorphic VT

Polymorphic VT with prolonged QT = Torsades de Pointes (TdP)

• Stop all QT-prolonging drugs
• IV Magnesium 1-2 g over 5-10 min (even if Mg levels are normal)
• Correct electrolyte imbalances (K⁺, Mg²⁺)
• Correct bradycardia - overdrive pacing at rate sufficient to suppress TdP bursts is definitive treatment
• Acquired long QT (drug-induced) with bradycardia: isoproterenol to increase rate temporarily
• Congenital long QT: beta-blockers + overdrive pacing; avoid beta-agonists

Polymorphic VT with normal QT

• Suspect acute ischemia/MI - check ECG and cardiac biomarkers
• Treat underlying ischemia urgently (reperfusion)
• If Brugada or early repolarization syndrome: isoproterenol IV, quinidine IV, overdrive pacing

Step 6: Identify and Reverse Precipitating Causes

Step 7: Electrical Storm

1. ACLS protocol
2. IV amiodarone infusion
3. Reduce sympathetic tone - this is the cornerstone:
   • Sedation, escalating to general anesthesia if needed
   • IV beta-blocker - propranolol (non-selective) more effective than metoprolol in one study; esmolol (500 mcg/kg load, then 50-200 mcg/kg/min) if short half-life desired
4. If ischemic cause: urgent coronary reperfusion + consider IABP
5. For ICD patients: confirm correct device function; consider disabling VT detection if patient is awake and tolerating VT, to allow shocks only when necessary
6. Emergent catheter ablation if initial measures fail
7. Advanced sympatholysis:
   • Stellate ganglion block
   • High thoracic epidural anesthesia
8. Hemodynamic support if needed:
   • IABP, percutaneous VAD (Impella/TandemHeart)
   • ECMO for refractory cases
   • Bridge to LVAD / transplant in terminal cardiomyopathy

Step 8: Long-Term Management (After Stabilization)

Evaluation

• 12-lead ECG (look for prior MI pattern, LBBB, Brugada, delta waves)
• Echocardiography - assess LV/RV function and structure
• Cardiac MRI - identify scar, infiltrative disease (sarcoid, ARVC, myocarditis)
• Coronary angiography - rule out ischemic substrate
• Genetic testing if non-ischemic cardiomyopathy (~40% are genetic) - important for family screening

ICD Implantation

• Secondary prevention ICD: indicated for virtually all patients who survive sustained VT/VF without reversible cause
• Primary prevention ICD: for patients with structural heart disease and reduced EF (LVEF ≤35%) even without prior VT

Antiarrhythmic Drug Therapy (Long-Term)

• Amiodarone - most effective antiarrhythmic for preventing recurrent VT; use as adjunct to ICD to reduce shock burden
• Sotalol - alternative in patients with structural heart disease
• Beta-blockers - first-line for idiopathic VT; adjunct in structural disease
• Drugs do NOT replace ICD; they reduce recurrence frequency

Catheter Ablation

• Indicated for recurrent VT despite antiarrhythmic drugs
• Effective for scar-related VT (ischemic and non-ischemic cardiomyopathy)
• A 2025 meta-analysis (Santoro et al., Europace 2025, PMID 41316690) comparing catheter ablation vs. antiarrhythmic drugs in ischemic heart disease found catheter ablation superior for reducing VT recurrence
• A 2024 meta-analysis (Askarinejad et al., Sci Rep 2024, PMID 39122752) supports catheter ablation as first-line in structural heart disease with preserved LVEF
• For idiopathic VT (RVOT, fascicular): ablation is highly curative (>90% success) and preferred over lifelong antiarrhythmic therapy

PVCs / Nonsustained VT (No Structural Disease)

• Asymptomatic: no treatment needed (no survival benefit from suppression)
• Symptomatic: beta-blocker (metoprolol 50 mg BID or atenolol 50 mg daily) - safe first choice
• High PVC burden causing cardiomyopathy: aggressive treatment with catheter ablation

Quick Summary Algorithm

VT detected
     │
     ├── No pulse ──► CPR + Defibrillation (ACLS)
     │
     └── Pulse present
              │
              ├── Unstable ──► Sedation → Synchronized Cardioversion
              │
              └── Stable
                       │
                       ├── Monomorphic ──► Procainamide (preferred)
                       │                   Amiodarone
                       │                   Lidocaine
                       │
                       └── Polymorphic
                                │
                                ├── Prolonged QT (TdP) ──► MgSO₄, pacing, stop QT drugs
                                └── Normal QT ──► Treat ischemia, isoproterenol (Brugada)

After stabilization:
  → Correct precipitants → Evaluate substrate → ICD ± ablation ± antiarrhythmics

• Tintinalli's Emergency Medicine, 9th ed. - p. 157 (acute management algorithm)
• Braunwald's Heart Disease, 12th ed. - pp. 556-558 (acute and long-term management)
• Goldman-Cecil Medicine, 2 vol. set - p. 590 (electrical storm management)
• Recent evidence: catheter ablation vs. AAD in ischemic VT (Santoro et al., Europace 2025, PMID 41316690) favors ablation for reducing VT recurrence

Wide Complex Tachycardia (WCT) - Step-by-Step Management

Step 1: Rule Out Two Dangerous Mimics First

Both require specific therapy - do not treat these with antiarrhythmics.

Step 2: Assess Hemodynamic Stability

Step 3: Unstable WCT → Immediate Synchronized Cardioversion

• Sedate if conscious and clinical status allows - do NOT delay if severely compromised
• Synchronized DC cardioversion (biphasic 100-200 J, escalate if needed)
• Follow with identification and reversal of precipitating causes
• If no pulse → unsynchronized defibrillation + CPR (ACLS protocol)

Step 4: Stable WCT → Classify the Rhythm

Is the rhythm REGULAR or IRREGULAR?

4A. REGULAR Monomorphic WCT

• 80-90% of regular WCTs are VT
• Older age + prior MI makes VT even more likely

ECG Differentiation: Brugada Criteria (sequential - stop when any criterion is YES = VT)

1. Absence of RS complex in ALL precordial leads (V1-V6)? → Yes = VT
2. R-to-S interval >100 ms in any one precordial lead? → Yes = VT
3. AV dissociation present? → Yes = VT
   • Look for independent P waves in inferior leads and V1-V2
   • Seen in only ~10% of VT on surface ECG but pathognomonic when present
   • Also look for: capture beats (narrow QRS earlier than expected) and fusion beats (intermediate morphology) - both = VT
4. VT morphology criteria in V1-V2 AND V6? → Yes = VT

Other Criteria (simpler alternatives):

Role of Adenosine in Stable Regular WCT:

• IV adenosine (6 mg rapid push, then 12 mg) can be used diagnostically
• If it terminates the tachycardia → was SVT (AVNRT, AVRT) or adenosine-sensitive VT
• If it causes transient AV block revealing underlying flutter/atrial tach → clarifies diagnosis
• If no response → likely VT
• Caution: rare forms of VT are adenosine-sensitive, so termination does NOT absolutely exclude VT

4B. IRREGULAR WCT

WPW / Pre-excited AF - CRITICAL RULES:

• NEVER give: AV nodal blockers (adenosine, verapamil, diltiazem, digoxin, metoprolol)
  • These block the AV node, forcing all conduction down the accessory pathway → extremely rapid ventricular rate → VF
• Treatment: Synchronized cardioversion (if unstable) or IV procainamide (if stable) - slows conduction in the accessory pathway

Step 5: Polymorphic WCT

Prolonged QT → Torsades de Pointes (TdP)

• IV Magnesium sulfate 2 g IV over 5-10 min (even if Mg levels normal)
• Stop all QT-prolonging drugs
• Correct K⁺ and Mg²⁺ deficits
• Overdrive pacing at rate >70 bpm (definitive - prevents TdP bursts)
• For acquired TdP with bradycardia: IV isoproterenol temporarily until pacing secured
• Congenital LQTS: beta-blockers + pacing; avoid sympathomimetics

Normal QT → Polymorphic VT

• Suspect acute myocardial ischemia/MI - immediate ECG, troponin, consider angiography
• Defibrillate if unstable
• Treat the ischemia (reperfusion)
• Brugada syndrome / early repolarization: isoproterenol IV, quinidine IV, overdrive pacing

Step 6: Pharmacologic Management of Stable WCT Assumed to Be VT

If clinical status deteriorates during pharmacologic treatment → immediate synchronized cardioversion.

Step 7: When Diagnosis Remains Uncertain in a Stable Patient

• Obtain a cardiology consult before empirical antiarrhythmics
• Unusual forms of WCT may need electrophysiology study
• A prior ECG (if available) is invaluable - compare QRS morphology during tachycardia vs sinus rhythm
• Prior history of structural heart disease, prior MI, or cardiomyopathy → high probability of VT

Quick Summary Algorithm

WCT (QRS ≥120 ms, rate >100)
     │
     ├─ Rule out Hyperkalemia / Na-channel toxicity (treat specifically)
     │
     ├─ NO PULSE → Defibrillate + CPR (ACLS)
     │
     ├─ PULSE + UNSTABLE → Sedation → Synchronized Cardioversion
     │
     └─ PULSE + STABLE
              │
              ├─ IRREGULAR?
              │       ├─ Bizarre/fast/variable → WPW-AF → Procainamide or Cardiovert
              │       ├─ Typical BBB morphology, irregular → AF with aberrancy → treat as AF
              │       └─ Twisting sinusoidal → TdP → MgSO₄, pacing, stop QT drugs
              │
              └─ REGULAR?
                      ├─ ASSUME VT (80-90% of cases)
                      ├─ Apply Brugada criteria → VT confirmed → Procainamide
                      ├─ Adenosine: diagnostic trial (clarifies SVT vs VT)
                      ├─ All Brugada criteria negative → SVT-aberrancy → treat as SVT
                      └─ Uncertain → Cardiology consult; treat as VT empirically

1. Hemodynamic stability ≠ SVT. Assume VT in any new regular WCT.
2. Never give verapamil/diltiazem empirically in WCT - can cause cardiovascular collapse in VT or WPW-AF.
3. Irregular WCT with very rapid rate = WPW-AF until proven otherwise - avoid all AV nodal blockers.
4. Procainamide is the safest broad-spectrum drug for undifferentiated stable WCT.
5. In any doubt, cardiovert.

• Rosen's Emergency Medicine, 9th ed. - pp. 1058-1059 (Brugada criteria, WCT differentiation)
• Tintinalli's Emergency Medicine, 9th ed. - pp. 157-159 (treatment table, ECG features, WPW)
• Frameworks for Internal Medicine - pp. 89-91 (classification, algorithms, TdP)
• Braunwald's Heart Disease, 12th ed. - p. 556 (differential diagnosis table)