Treatment for Torsades de Pointes During Cardiac Arrest
Administer intravenous magnesium sulfate 1-2 grams IV over 1-2 minutes immediately—this is the definitive first-line treatment for torsades de pointes, regardless of baseline serum magnesium levels. 1, 2
Clinical Recognition and Context
The patient presents with a "twisting type of pattern" multifocal VT, which is the pathognomonic description of torsades de pointes 3. The cachectic appearance with diminished muscle mass in a patient with alcohol use disorder strongly suggests underlying electrolyte abnormalities (hypokalemia, hypomagnesemia) and malnutrition—classic predisposing factors for acquired long QT syndrome and torsades 3, 4, 5.
Why Magnesium is the Correct Answer (Option C)
Magnesium sulfate is the treatment of choice for torsades de pointes and has Class IIa recommendation from ACC/AHA/ESC guidelines. 3 The evidence supporting magnesium includes:
- Multiple studies demonstrate effectiveness even when serum magnesium levels are normal 3, 1
- Magnesium prevents reinitiation of torsades rather than just converting the rhythm 2
- It is safe to administer during active resuscitation and works rapidly 4, 6
- The dose is standardized: 1-2 grams IV over 1-2 minutes for adults 1, 2, 7
Why the Other Options Are Incorrect
Epinephrine (Option A)
While epinephrine is part of standard ACLS for cardiac arrest, it does not specifically address the underlying mechanism of torsades de pointes and may worsen the arrhythmia by increasing catecholamine stimulation 3. Epinephrine would be given as part of routine CPR cycles but is not the specific treatment for this rhythm.
Amiodarone (Option B)
Amiodarone is explicitly contraindicated in torsades de pointes because it prolongs the QT interval and can worsen the arrhythmia. 4, 7 Amiodarone is recommended for monomorphic VT or polymorphic VT with normal QT (ischemic VT), but not for torsades 3. This is a critical distinction—using standard antiarrhythmic drugs that prolong repolarization will aggravate torsades rather than terminate it 4, 5.
Atropine (Option D)
Atropine has limited utility in this scenario. While increasing heart rate can help prevent pause-dependent torsades recurrence, atropine is not the primary treatment and would only be considered after magnesium administration if bradycardia persists 3, 4.
Complete Management Algorithm for This Patient
Continue high-quality CPR with defibrillation as needed (standard ACLS protocol continues) 1, 2
Administer magnesium sulfate 1-2 g IV over 1-2 minutes immediately 1, 2, 7
Withdraw any QT-prolonging medications (though this patient is already in arrest, consider what may have been administered) 3, 1, 2
Correct electrolyte abnormalities once ROSC achieved:
If torsades recurs after ROSC, consider:
Critical Pitfalls to Avoid
Do not administer Class IA, IC, or III antiarrhythmics (quinidine, procainamide, amiodarone, sotalol) as these prolong QT interval and will worsen torsades. 4, 5, 7 This is the most dangerous error in torsades management.
Calcium has no role in torsades treatment and should not be given (it is only mentioned as a reversal agent for magnesium toxicity in pediatric protocols, not as primary therapy). 2
Recognize that magnesium works regardless of baseline serum levels—do not delay administration waiting for laboratory results. 1, 2, 7
Special Considerations for This Patient
Given the history of alcohol use disorder and cachexia, this patient likely has chronic malnutrition with multiple electrolyte deficiencies 4, 5. After achieving ROSC, aggressive electrolyte repletion will be essential to prevent recurrence, and investigation for other QT-prolonging factors (medications, structural heart disease) should be undertaken 5, 7.
The answer is C: Magnesium IV.