Myocardial injury after temporary transvenous cardiac pacing1. Meng Liu, MD2. Pingsheng Wu, MDFrom Cardiology Department, Nanfang Hospital, Southern Medical University, Guangzhou, China; Emergency Department, Hunan Provincial People’s Hospital, Medical School of Hunan Normal University, Changsha, ChinaCorrespondence to Pingsheng Wu. Cardiology Department, Nanfang Hospital, Southern Medical University. No. 1838, north Guangzhou Road, Guangzhou, China.Keywords: Temporary pacemaker; Temporary transvenous cardiac pacing; Myocardial injury; Bradyarrhythmia; Perioperative myocardial injury.AbstractIntroduction: It is not unusual for temporary transvenous cardiac pacing (TVCP) leads to penetrate and occasionally perforate the right ventricular wall, which generally is asymptomatic. The definition of myocardial injury is evidence of elevated cardiac troponin (cTn) values above the 99th percentile upper reference limit (URL). Myocardial injury is associated with an adverse prognosis. The present study was designed to evaluating myocardial injury complicated by TVCP.Methods: Retrospective study from August 2018 to March 2020, 33 consecutive patients undergo elective TVCP support for non-cardiac procedures, 22 of them had cardiac biomarkers assays before and after TVCP. These 22 eligible patients had a median age of 66 (50-83) years, 6 (27.3%) were women, and all baseline cTn <1 URL. Compare cardiac biomarkers before and after TVCP.Results: 20 (91%, N=22) patients detect cTn >1 URL after pacing. Paired t-test compare before and after pacing leads insertion showed a mean cTn elevation of 3.599 (95% CI, 1.566 to 5.632, P<0.01）URL, and no significantly creatine kinase-MB elevation of 0.1550 (95% CI, -0.01239 to 0.3224, P>0.05 ) URL.Conclusion: This study demonstrates a high incidence of substantial myocardial injury by TVCP, which should be concerned.