Electrophysiologic effects of lorcainide on the accessory pathway in the Wolff-Parkinson-White syndrome.

Abstract

The electrophysiologic effects of lorcainide, a class I antiarrhythmic agent with local anesthetic properties, were studied in 20 patients with the Wolff-Parkinson-White syndrome. After intravenous administration of lorcainide (2 mg/kg), the sinus cycle length decreased in all patients from 705 +/- 117 to 636 +/- 94 ms (p less than 0.001). The atrioventricular conduction time lengthened from 84 +/- 22 to 94 +/- 22 ms (p less than 0.01) and the QRS duration increased from 92 +/- 19 to 120 +/- 29 ms (p less than 0.001). The effective refractory period of the atrium increased from 230 +/- 27 to 243 +/- 35 ms (p less than 0.05), whereas the ventricular refractoriness was unaffected. Retrograde conduction over the accessory pathway was blocked in 5 of 18 patients after lorcainide; in the remaining 13 patients a prolongation from 107 +/- 32 to 162 +/- 57 ms (p less than 0.001) was found. Anterograde conduction over the accessory pathway was blocked in 6 patients, and in all other patients it increased considerably. Circus movement tachycardia could be induced in 14 patients before and in 10 patients after the drug. The shortest R-R interval during tachycardia lengthened from 326 +/- 40 to 364 +/- 67 ms (p less than 0.05). The tachycardia zone was unaffected by lorcainide. In 15 patients atrial fibrillation was induced. After lorcainide anterograde conduction during atrial fibrillation was blocked (n = 5). The shortest R-R interval over the accessory pathway during induced atrial fibrillation increased from 228 +/- 35 to 304 +/- 103 ms (p less than 0.05). Intravenous administration of lorcainide produced a pronounced negative dromotropic effect on the conduction properties of the accessory pathway. Lorcainide appears to be a promising new antiarrhythmic agent in patients with the Wolff-Parkinson-White syndrome.

• Authors: W Kasper, N Treese, T Meinertz, E Jähnchen, T Pop
• Journal: The American journal of cardiology (Am J Cardiol) Vol. 51 Issue 10 Pg. 1618-22 (Jun 1983) ISSN: 0002-9149 [Print] United States
• PMID: 6858867 (Publication Type: Journal Article)

Chemical References

• Anti-Arrhythmia Agents
• Benzeneacetamides
• Piperidines
• lorcainide

Topics

• Adolescent
• Adult
• Aged
• Anti-Arrhythmia Agents (therapeutic use)
• Atrial Fibrillation (physiopathology)
• Benzeneacetamides
• Drug Evaluation
• Electrocardiography
• Female
• Heart Conduction System (drug effects)
• Humans
• Male
• Middle Aged
• Piperidines (therapeutic use)
• Tachycardia (physiopathology)
• Wolff-Parkinson-White Syndrome (drug therapy, physiopathology)