IRCT20120215009014N350 IRCT 2020-03-28 Hamedan University of Medical Sciences Effect of botulinum toxin injection versus placebo injection in fat pad around the heart on the incidence of intra-hospital atrial fibrillation after open-heart surgery: a double-blind randomized clinical trial Effect of botulinum toxin injection versus placebo injection in fat pad around the heart on the incidence of intra-hospital atrial fibrillation after open-heart surgery: a double-blind randomized clinical trial 2020-01-21 anticipated 60 Complete https://irct.ir/trial/46729 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Randomization description: Random assignment of the patients to the intervention and control groups through the drawing of lots. To do this, we prepare two sheets and write "intervention" on one sheet and "control" on another. Then, by referring each patient, one of the sheets will be randomly taken and the patient will be assigned to the intervention or control group, Blinding description: The drug and placebo are prescribed through injection and their shapes are perfectly the same. Therefore, patients will be unaware of the type of intervention. The physician who will examine the patients will not be aware of the intervention. Thus, the trial will be run as double-blind. 2 Atrial fibrillation. Intervention 1: Injection of Botulinum Toxin Type A (manufacture by Dysport Pharmaceutical Co.) 50 unit with insulin needle in fat pad around the heart single does. Intervention 2: Control group: Injection of serum normal saline 0.9% one unit with insulin needle in fat pad around the heart single does. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is It depends on the situations and the results of the study as well as the approval of the financial supporting organization.