ACLS review: Wide Complex Tachycardia (WCT) Part 9

Torsades de pointes

Torsades de pointes

Torsades de pointes

·         Occurs in a setting of bradycardia and prolongation of the QT interval.

·         A continuously changing VT morphology is often described as appearing to rotate or turn around the ECG baseline.
·         Polymorphic VT, including torsades, frequently terminates, but the arrhythmia will recur and seldom remains stable.
·         should be treated immediately because of the frequent transition to unstable VT

Note:  If a long QT interval is observed during sinus rhythm (ie, the VT is torsades de pointes), the first step is to stop medications known to prolong the QT interval. Correct electrolyte imbalance and other acute precipitants

Treatment of Torsades de Pointes

·         Consultation with cardiologist
·         Stop medications known to prolong the QT interval.
·         Correct electrolyte imbalance and any other acute precipitants.
·         IV magnesium
·         Pacing
·         Isoproterenol
·         Beta blockers

Note: One adult case series showed that isoproterenol or ventricular pacing can be effective in terminating torsades de pointes associated with bradycardia and drug-induced QT prolongation.

Polymorphic VT associated with familial long QT syndrome may be treated with IV magnesium, pacing, and/or beta blockers; isoproterenol should be avoided.

Polymorphic VT associated with acquired long QT syndrome may be treated with IV magnesium. The addition of pacing or IV isoproterenol may be considered when polymorphic VT is accompanied by bradycardia or appears to be precipitated by pauses in rhythm.

In the absence of a prolonged QT interval, the most common cause of polymorphic VT is myocardial ischemia. In this situation IV amiodarone and beta-blockers may reduce the frequency of arrhythmia recurrence

Expert  Consultation

·         Stable patients may await expert consultation because treatment has the potential for harm.

·         Sequential use of 2 or more drugs may have adverse effects: bradycardia, hypotension, and torsades de pointes

·         Seek expert consultation for tachycardias not responsive to medications

·         Seek consultation for long term management

References

Aehlert, Barbara. ACLS Quick Review Study Guide, 2nd edition.  Mosby, inc.  St. Louis, Mo. 1994.

Neumar RW, Otto CW, Link MS, Kronick SL, Shuster M, Callaway CW, Kudenchuk PJ, Ornato JP, McNally B, Silvers SM, Passman RS, White RD, Hess EP, Tang W, Davis D, Sinz E, Morrison LJ. Part 8: adult advanced cardiovascular life support: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2010;122(suppl 3):S729–S767.



Reviewed 2/28/16