What is the management for a patient in ventricular tachycardia (Vtach) cardiac arrest?

Management of Ventricular Tachycardia Cardiac Arrest

Pulseless ventricular tachycardia is treated identically to ventricular fibrillation with immediate unsynchronized high-energy defibrillation followed by CPR, not synchronized cardioversion. 1

Immediate Recognition and Initial Response

• Confirm pulselessness immediately – pulseless VT is a cardiac arrest rhythm requiring defibrillation, not cardioversion 1, 2
• Activate the response team capable of identifying the mechanism and carrying out prompt intervention 1
• Begin high-quality CPR immediately if a defibrillator is not immediately available 1
• Do not use synchronized cardioversion for pulseless VT, as the device may not sense a QRS wave and shock delivery may fail 1

Defibrillation Strategy

Deliver unsynchronized high-energy shocks (defibrillation doses) as soon as the defibrillator is available:

• Use biphasic waveform defibrillators with initial energy of 200J for biphasic devices 1
• If using monophasic waveforms, start at 360J 1
• Minimize pre-shock and peri-shock pauses – charge the defibrillator during chest compressions to maximize chest compression fraction 3
• Deliver a single shock followed by immediate resumption of CPR for 2 minutes before rhythm check 1
• Do not deliver 3-shock sequences; single shocks with immediate CPR have replaced this outdated approach 1

Critical timing considerations:

• If the arrest is witnessed and a defibrillator is immediately available, defibrillate without delay 3
• If there will be any delay in obtaining the defibrillator, perform CPR while the device is being obtained 3
• Shorter pre-shock pauses are associated with higher survival rates 3

Post-Shock CPR Protocol

• Resume chest compressions immediately after shock delivery without pausing to check rhythm or pulse 1
• Continue high-quality CPR for 2 minutes (5 cycles) before the next rhythm check 1
• Coordinate CPR with defibrillation to minimize interruptions in chest compressions 1

Medication Administration

After the first shock and during CPR:

• Establish IV or IO access without interrupting chest compressions 1
• Administer epinephrine 1 mg IV every 3-5 minutes 1
• Consider amiodarone 300 mg IV bolus for refractory VF/pulseless VT after the first shock 1, 4
• Amiodarone is FDA-approved for frequently recurring VF and hemodynamically unstable VT refractory to other therapy 4
• A second dose of amiodarone 150 mg IV may be given for recurrent or refractory VF/pulseless VT 4
• Lidocaine 1-1.5 mg/kg IV may be considered if amiodarone is unavailable or contraindicated 1

Refractory VF/Pulseless VT Management

If the rhythm remains VF/pulseless VT after 3 or more defibrillation attempts:

• Continue the defibrillation-CPR-epinephrine cycle 1
• Ensure adequate amiodarone dosing has been administered 4
• Consider double defibrillation (dual sequential external defibrillation) using two biphasic defibrillators with pads in anterolateral and anterior-posterior configurations 3
• Verify correct pad placement and consider changing pad position if initial attempts fail 1
• Recurrent VF is common (48% within 2 minutes, 74% during prehospital care), and repeated shocks may be necessary 5

Airway Management

• Intubate the patient during CPR without causing undue delay in chest compressions or defibrillation 1
• Neither intubation nor IV access should delay defibrillation attempts 1

Reversible Causes

Evaluate and correct potential reversible causes during CPR cycles:

• Correct electrolyte imbalances, particularly hypokalemia and hypomagnesemia 1
• Assess for acute myocardial ischemia – consider emergent coronary angiography in appropriate candidates 1
• Rule out hypoxia, acidosis, hypothermia, and toxins 2

Post-Resuscitation Care

If return of spontaneous circulation is achieved:

• Direct admission to the catheterization laboratory is recommended for comatose survivors with STEMI criteria on post-resuscitation ECG 1
• Consider coronary angiography within 2 hours for comatose survivors without ST-elevation, particularly if hemodynamically unstable 1
• Initiate beta-blocker therapy during hospital stay and continue thereafter in all patients without contraindications 1
• Consider ICD implantation for secondary prevention after stabilization 1

Common Pitfalls to Avoid

• Never use synchronized cardioversion for pulseless VT – this is a fatal error as the device may fail to deliver a shock 1
• Do not delay defibrillation to establish IV access or intubate 1
• Avoid prolonged pulse checks or rhythm analysis that interrupt chest compressions 1, 3
• Do not use prophylactic antiarrhythmic drugs other than beta-blockers, as they may be harmful 1
• Do not abandon resuscitation while the rhythm remains VF/pulseless VT – recurrent VF is common and shocks that terminate later episodes increasingly result in sustained organized rhythms 1, 5
• Avoid using drop counter infusion sets for amiodarone, as they may underdose by up to 30%; use volumetric infusion pumps 4