Related Experiment Videos
Cycle length-dependent effects on normal and abnormal intraventricular electrograms: effect of procainamide.
C Schmitt1, A H Kadish, W C Balke
1Clinical Electrophysiology Laboratory, Hospital of the University of Pennsylvania, Philadelphia 19104.
Journal of the American College of Cardiology
|August 1, 1988
Summary
Procainamide significantly prolonged QRS width in patients with prior myocardial infarction, independent of pacing cycle length. This antiarrhythmic drug
Area of Science:
- Cardiology
- Electrophysiology
- Pharmacology
Background:
- Patients with prior myocardial infarction often experience ventricular arrhythmias.
- Procainamide is an antiarrhythmic drug used to manage cardiac rhythm disturbances.
- Understanding drug effects on electrophysiological properties is crucial for patient management.
Purpose of the Study:
- To investigate the impact of procainamide on cycle length-dependent electrophysiological changes.
- To assess procainamide's effect on QRS width in patients with previous myocardial infarction.
Main Methods:
- Intracardiac bipolar electrograms recorded from abnormal left ventricular and normal right ventricular sites.
- Right ventricular apex pacing performed at various cycle lengths (600/500, 400, 300 ms).
- Procainamide administered at a mean concentration of 9.1 +/- 2.0 micrograms/ml.
Main Results:
- Procainamide significantly increased mean QRS width at all paced cycle lengths (p < 0.01).
- QRS widening ranged from +18% at 600/500 ms to +31% at 300 ms.
- No significant changes in QRS width or electrogram characteristics were observed in the control state.
Conclusions:
- Procainamide prolongs QRS duration in patients with prior myocardial infarction.
- This effect is independent of the pacing cycle length.
- Findings highlight procainamide's impact on ventricular conduction properties.