Related Experiment Videos
Electrical proarrhythmia with procainamide: a new ICD-drug interaction
E Fiksinski1, D Martin, F Venditti
1Cardiac Electrophysiology Laboratory, Lahey Clinic Medical Center, Burlington, Massachusetts 01805.
Journal of Cardiovascular Electrophysiology
|February 1, 1994
Summary
A patient on procainamide experienced frequent defibrillator shocks for ventricular tachycardia, which were surprisingly terminated by low-energy discharges. This suggests a unique procainamide effect on defibrillation, not seen with other drugs.
Area of Science:
- Cardiology
- Electrophysiology
- Pharmacology
Background:
- A 78-year-old male patient had a transvenous cardioverter-defibrillator system implanted.
- The patient was undergoing oral procainamide therapy for an unspecified condition.
Observation:
- The patient experienced frequent, inappropriate shocks from his cardioverter-defibrillator.
- Electrophysiologic testing revealed that maximal energy shocks failed to terminate ventricular tachycardia.
- However, low-energy discharges consistently terminated the ventricular tachycardia.
Findings:
- Procainamide administration did not alter the patient's defibrillation threshold.
- Disopyramide and mexiletine therapies did not replicate the observed phenomenon.
- This suggests a specific, potentially idiosyncratic, electrophysiologic effect of procainamide.
Implications:
- This case highlights a potential, previously unreported interaction between procainamide and cardioverter-defibrillator function.
- Further investigation is warranted to understand this unique electrophysiologic response.
- Clinicians should be aware of this potential adverse effect when prescribing procainamide to patients with defibrillators.