Introduction: Myocardial infarction is one of the major health problems worldwide that may be associated with hemodynamic instability and cardiac arrhythmias. The aim of this study was to investigate the effects of Peppermint aroma on vital signs and cardiac arrhythmias in patients with acute myocardial infarction (AMI).

  Methods: This is a randomized clinical trial. 126 patients with AMI were enrolled in the study with purposive sampling and randomly divided into two groups. In intervention group, pads saturated with 0.2 ml of peppermint oil and in control group pads with normal saline were attached to the patient's clothes on front of chest. Data was collected using a demographic questionnaire and visual analog scale for nausea. Data was analyzed using SPSS version 19 by Chi-square, independent t-test, and Generalized Estimating Equations.

  Results: In this study, the mean age of patients was 62/1±12/3. Most subjects were male, non-smokers, with no history of motion sickness. There was no significant difference between groups in terms of demographics and risk factors. Results showed, although the incidence of cardiac arrhythmias in intervention group was lower than control group but the difference was not significant. Also, there was no statistical difference between the two groups regarding vital signs.

  Conclusion: Peppermint aromatherapy is noninvasive, safe, and convenient. It works rapidly and provokes nearly no side effect and is well accepted and tolerated by patients. However, further studies should be performed to investigate the possible effect of aromatherapy on arrhythmias and vital signs in patients with AMI.