December 1, 1993Journal of Cardiovascular Pharmacology
Mechanisms of Ventricular Arrhythmia During Amitriptyline Toxicity
Key result
Amitriptyline infusion induced ventricular tachycardia in 100% of dogs with accelerated pacing and 83% with intact sinus nodes, but in 0% of dogs with fixed pacing at 100 beats/min.
Why the study?
Does amitriptyline infusion induce ventricular tachycardia through rate-dependent mechanisms or afterdepolarizations in a dog model?
Population
23 chloralose-anesthetized dogs divided into three groups based on sinus node status and pacing strategy.
Comparison
Amitriptyline infusion in a graded fashion. vs Comparison between different pacing strategies…
Design
Preclinical
Authors
Discussion
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Implication
Amitriptyline's proarrhythmic effects in dogs warrant caution in toxicity; leaves open human translation and prospective validation.
Structured PICO
Does amitriptyline infusion induce ventricular tachycardia through rate-dependent mechanisms or afterdepolarizations in a dog model?
P
Population
23 chloralose-anesthetized dogs subjected to graded amitriptyline infusion under different pacing conditions to study ventricular arrhythmia mechanisms.
I
Intervention
Amitriptyline infusion in a graded fashion (0.5-1 mg/kg/min).
C
Comparator
Comparison between different pacing strategies and heart rates (Group A vs Group B vs Group C).
O
Outcome
Induction of ventricular tachycardia (VT) and electrophysiological changes (QRS prolongation, APD50, APD90, afterdepolarizations).surrogate
Amitriptyline-induced ventricular tachycardia is highly rate-dependent and associated with QRS prolongation rather than afterdepolarizations.
Cite This Study
Ansel et al. (1993) studied Amitriptyline toxicity (n=23). Amitriptyline infusion vs. Different pacing protocols (fixed vs accelerated vs intact sinus node) was evaluated on Ventricular tachycardia (VT) induction. Amitriptyline infusion induced ventricular tachycardia in 100% of dogs with accelerated pacing and 83% with intact sinus nodes, but in 0% of dogs with fixed pacing at 100 beats/min.