Exercise-induced ventricular tachycardia in a case with hypertrophic cardiomyopathy taking cibenzoline

Area of Science:

• Cardiology
• Electrophysiology
• Pharmacology

Background:

• Hypertrophic cardiomyopathy (HCM) is a genetic heart condition.
• Class I antiarrhythmic drugs, like cibenzoline, block sodium channels.
• Proarrhythmia is a potential adverse effect of antiarrhythmic medications.

Observation:

• A 17-year-old female patient with HCM was resuscitated from ventricular fibrillation.
• Ventricular tachycardia was induced during exercise stress testing while the patient was taking cibenzoline.
• The induced arrhythmia was attributed to the use-dependent sodium channel blockade of cibenzoline.

Findings:

• Cibenzoline demonstrated a proarrhythmic effect in a patient with hypertrophic cardiomyopathy.
• Exercise-induced tachycardia was exacerbated by the Class I antiarrhythmic drug.
• The Na channel blockade effect of cibenzoline was implicated in the proarrhythmic event.

Implications:

• Caution is advised when using Class I antiarrhythmic drugs in patients with HCM.
• Clinicians must consider the proarrhythmic potential of antiarrhythmics, particularly with increasing heart rate.
• Careful monitoring and risk assessment are crucial for managing arrhythmias in HCM patients on specific medications.