Abstract
In 1955, Burn et al. (1) succeeded in the maintenance of atrial fibrillation by continuous infusion of acetylcholine (ACh) in the dog heart-lung preparation when atrial fibrillation was induced by electric stimulation of auricle. Recently, Hashimoto et al. (2) arranged an adequate method for the selective use of drugs into the sinus node artery in situ by modifying the original preparation developed by James and Nadeau (3), Hashimoto et al. (4) observed that atrial fibrillation was regularly induced by the administration of ACh into the sinus node artery under constant pressure perfusion. They analyzed the mechanism for induction of atrial arrhythmia with ACh, assuming the necessary participation of adrenergic mechanism with essential cholinergic effect of ACh. More recently, Nakayama et al. (5) obtained sustaining atrial fibrillation by continuous infusion of a relatively small amount of ACh directly into the sinus node artery.
In the present study, the authors observed regularly an occurrence of a sustaining atrial fibrillation by single injection of carbachol, methacholine or bethanechol into the sinus node artery, and compared with the atrial fibrillation induced by ACh.
