Potential use of prophylactic intracoronary atropine in reducing reperfusion vagal reflex-related events in ST-elevation myocardial infarction

In this study, we evaluated the potential use of atropine in reducing reperfusion vagal reflex-related events during emergency percutaneous coronary intervention (PCI) for acute inferior ST-elevation myocardial infarction (STEMI). Retrospectively, we included 142 patients with inferior wall STEMI, who were treated between October 2015 and October 2020, in this study. The patients were divided into an experimental group (n = 70) and a control group (n = 72) depending on whether they received prophylactic intracoronary atropine. The experimental group was then subdivided into a low-dose group (0.5 – 1 mg atropine, n = 40) and a high-dose group (2 mg atropine, n = 30). We compared the incidence of reperfusion vagal reflex-related events and the application of temporary pacemakers between these groups. The results showed that the incidence of bradycardia (24.3% vs. 45.8%, P = 0.007), hypotension (18.6% vs. 40.3%, P = 0.005), ventricular tachycardia (4.3% vs. 19.4%, P = 0.005), and ventricular fibrillation (8.6% vs. 20.8%, P = 0.040) as well as the application of temporary pacemakers (14.3% vs. 29.2%, P = 0.032) were all much lower (all P < 0.05) in the experimental group than in the control group. In addition, the incidence of bradycardia (10% vs. 35%, P = 0.016), hypotension (6.7% vs. 27.5%, P = 0.027), ventricular tachycardia (6.7% vs. 25%, P = 0.044), and ventricular fibrillation (0 vs. 15%, P = 0.034) as well as the application of temporary pacemakers (3.3% vs. 22.5%, P = 0.036) were all much lower (all P < 0.05) in the high-dose group than the low-dose group. Our findings demonstrate that atropine pretreatment could prevent reperfusion vagal reflex-related events and reduce the application of temporary pacemakers during emergency PCI for acute inferior STEMI. These effects can be significantly enhanced by high-dose (2 mg) atropine pretreatment.