Torsades de pointes after adenosine administration.

Area of Science:

• Cardiology
• Pharmacology
• Electrophysiology

Background:

• Adenosine is commonly used to treat supraventricular tachycardias.
• Adenosine can induce various transient arrhythmias, including premature atrial contractions (PACs), premature ventricular contractions (PVCs), sinus bradycardia, and atrial fibrillation.
• Transient polymorphic ventricular tachycardia (VT), specifically torsades de pointes (TdP), has been reported following adenosine administration, particularly in patients with Long QT Syndrome (LQTS).

Observation:

• A case report details a 27-year-old woman who received 6 mg of adenosine for paroxysmal supraventricular tachycardia (PSVT).
• Following the termination of PSVT, the patient developed torsades de pointes.
• The polymorphic VT episode persisted for an unusually long duration of 17 seconds before spontaneously resolving.

Findings:

• This case represents the longest documented episode of adenosine-induced torsades de pointes in a patient with a normal QT interval.
• The findings challenge the assumption that adenosine-induced TdP is always brief, even in individuals without pre-existing QT interval prolongation.

Implications:

• Clinicians should be aware of the potential for prolonged torsades de pointes following adenosine administration, even in patients with normal baseline QT intervals.
• This case highlights the importance of vigilant cardiac monitoring after adenosine administration, particularly in susceptible individuals.
• Further research may be warranted to elucidate the mechanisms underlying prolonged adenosine-induced TdP in the absence of LQTS.