ECG Diagnosis: Polymorphic Ventricular Tachycardia, consistent with Torsades de Pointes
The ECG shows a wide-complex tachycardia with changing QRS morphology and a characteristic twisting appearance around the baseline, consistent with polymorphic ventricular tachycardia, specifically torsades de pointes.
Torsades de pointes is associated with QT prolongation. Amiodarone can further prolong the QT interval and may worsen or perpetuate torsades.
Acute management of torsades focuses on:
🟣 IV magnesium
🟣 Correction of hypokalemia and other electrolyte abnormalities
🟣 Withdrawal of QT-prolonging drugs
🟣 Defibrillation if the patient is unstable or the VT is sustained
What about verapamil?
This is where an important nuance exists.
Verapamil is contraindicated in most forms of ventricular tachycardia and should not be given to an undifferentiated wide-complex tachycardia. It can cause profound hypotension and cardiovascular collapse.
However, there is an important exception: fascicular ventricular tachycardia, also called idiopathic left ventricular VT or Belhassen VT.
Fascicular VT is a rare idiopathic VT, usually occurring in younger patients without structural heart disease. It originates within the left ventricular fascicular system and can sometimes resemble supraventricular tachycardia with aberrancy.
Unlike most VTs, fascicular VT is calcium-dependent and is characteristically responsive to intravenous verapamil. This led to the terms verapamil-responsive VT and Belhassen VT.
Therefore, saying simply verapamil should never be used in VT would be incorrect.
(Apologies for the poor formulation of the original question)
📸: Fascicular VT
Which of the following drugs should NOT be used in the management of ventricular tachycardia ?
A) Amiodarone
B) Lidocaine
C) Verapamil
D) Procainamide