Mechanism for Pituitary Adenylate Cyclase-Activating Polypeptide-Induced Atrial Fibrillation
Version of Record online: 13 AUG 2003
© Futura Publishing Company, Inc. 2001
Journal of Cardiovascular Electrophysiology
Volume 12, Issue 12, pages 1381–1386, December 2001
How to Cite
HIROSE, M., LEATMANORATN, Z., LAURITA, K. R. and CARLSON, M. D. (2001), Mechanism for Pituitary Adenylate Cyclase-Activating Polypeptide-Induced Atrial Fibrillation. Journal of Cardiovascular Electrophysiology, 12: 1381–1386. doi: 10.1046/j.1540-8167.2001.01381.x
- Issue online: 13 AUG 2003
- Version of Record online: 13 AUG 2003
- Manuscript received 14 July 2000; Accepted for publication 16 October 2001.
- Cited By
- pituitary adenylate cyclase-activating polypeptide;
- effective refractoriness;
- atrial fibrillation;
- autonomic nervous system
Pituitary Adenylate Cyclase-Activating Polypeptide-Induced AF. Introduction: Pituitary adenylate cyclase-activating polypeptide (PACAP), which activates intracardiac postganglionic parasympathetic nerves, has a greater profibrillatory effect than vagal stimulation. However, the mechanism responsible for this is unclear.
Methods and Results: We examined the effective refractory period (ERP), conduction time, and incidence of atrial fibrillation (AF) induced by a single premature extrastimulus at four atrial sites as well as the AF cycle length at 65 atrial sites in 12 autonomically decentralized, open chest, anesthetized dogs. These parameters were measured in the control condition, during cervical vagal stimulation, and after PACAP administration. PACAP shortened the ERP to a similar extent at all four sites. Vagal stimulation shortened the ERP primarily at the high right atrium, but not at the other three sites. Global dispersion of ERP and variation in the AF cycle length (P < 0.01) were less after PACAP than during vagal stimulation. A premature extrastimulus induced AF more frequently after PACAP than during vagal stimulation (P < 0.001). The ERP at the pacing site was shorter when AF was induced than when it was not induced regardless of the intervention and the pacing site. Conduction time following premature beats that induced AF was shorter after PACAP than during vagal stimulation (P < 0.01).
Conclusion: Global ERP shortening contributes to the greater profibrillatory effect of PACAP. In addition, the decreased conduction time following premature beats may be associated with AF induction in this model.