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Suppression of ventricular automaticity by antidysrhythmic agents.
European Journal of Pharmacology
|September 1, 1975
Summary
Four antiarrhythmic drugs (quinidine, procainamide, lidocaine, propranolol) were tested for their effects on ventricular automaticity in dogs. All drugs depressed automaticity, with propranolol being effective at lower doses.
Area of Science:
- Cardiovascular Pharmacology
- Cardiac Electrophysiology
Background:
- Ventricular dysrhythmias can arise from abnormal automaticity.
- Understanding the impact of antiarrhythmic agents on automaticity is crucial for treating cardiac arrhythmias.
Purpose of the Study:
- To investigate the effects of quinidine, procainamide, lidocaine, and propranolol on ventricular automaticity.
- To compare the efficacy of these agents in depressing automaticity.
Main Methods:
- Anesthetized dogs with atrioventricular (A-V) block were used.
- The effects of four antiarrhythmic agents on ventricular rate and overdrive suppression were measured.
Main Results:
- Quinidine, procainamide, lidocaine, and propranolol all slowed ventricular rate in A-V blocked dogs.
- These agents, particularly lidocaine and propranolol, prolonged overdrive suppression, indicating depressed automaticity.
- Propranolol demonstrated efficacy at lower doses compared to its antiarrhythmic effects in experimental models.
Conclusions:
- All four tested antiarrhythmic agents possess the ability to depress ventricular automaticity.
- Propranolol may be a particularly effective agent for managing arrhythmias related to automaticity due to its dose-dependent effects.