The incidence of infections after permanent pacemaker (PPM) implantation ranges from 0.5% to 5%, with a mean of 2% [[1], [2]]. Of these, cases of Cardiac deviceCrelated infective endocarditis (CDIE) account for 10% of all infections [[3]]. Infective endocarditis after permanent pacemaker implantation is very rare and its treatment is very difficult, with high mortality and disability rates. To summarize our experience in the treatment of this disease, we analyzed the data of patients with pacemaker-associated infective endocarditis treated at our institution over a 10-year period. We analyzed the data of patients with pacemaker-associated infective endocarditis treated at our hospital over the past 10 years to facilitate clinicians’ understanding of the disease and their selection of the correct treatment. General data: There were 8 cases of pacemaker-associated infective endocarditis, 5 men and 3 women, aged 52±20 years (21-74 years), hospitalized from January 1, 2001, to April 31, 2010. All patients met Duke’s criteria for clinical features and were diagnosed with infective endocarditis. Surgical methods: Seven of the eight patients in this group underwent surgical open-heart surgery to remove the intracardiac electrodes and permanent pacing device. one case chose to remove the intracardiac electrodes and remove the extracardiac pacing device via the vein. In one case, the intracardiac electrode was removed intravenously to remove the extracardiac pacing device. The open-heart surgery was performed with a median chest opening, ascending aorta cannulation, superior vena cava cannulation at right angles, and inferior vena cava cannulation to establish extracorporeal circulation. The upper and lower vena cava are blocked, the right atrium is incised, the intracardiac portion of the pacing electrode is removed under direct vision, the pacing electrode is cut at the entrance of the superior vena cava, the intracardiac portion of the electrode is removed, the tricuspid valve is repaired at the same time if there is tricuspid regurgitation, and the right atrial incision is closed. The epicardial temporary pacing lead is placed and temporary right ventricular epicardial pacing is applied. The extracorporeal circulation is stopped, and after neutralization of fisetin, the extracorporeal circulation is withdrawn, and the skin is incised at the original pacemaker implantation site before or after chest closure, and the permanent pacemaker battery and residual electrodes are removed. The removal of the trans-deep vein electrodes was performed in the same way as in the literature [[4]]. Follow-up: All cases were followed up through outpatient follow-up or by telephone, which included patients’ complaints, the presence of systemic infections such as fever or local inflammatory manifestations, and relevant treatments Statistical description: because of the small sample, statistics were expressed as mean ± standard deviation, minimum value, and maximum value. Results All patients in this group developed infections within 1 year after the second or more pacemaker surgical operations. Two patients had local infection before the manifestation of systemic infection. 7 cases were successfully removed from the pacing electrodes and batteries under extracorporeal circulation in open-heart surgery. In all seven cases, the pacing lead was found to be clearly superfluous. One of these seven patients had coronary artery bypass grafting in conjunction with coronary artery disease, one had aortic valve replacement in conjunction with aortic valve redundancy, and two patients required tricuspid valvuloplasty. The postoperative monitoring period was 1-2 days, and a temporary pacemaker was used to maintain the ventricular rate after surgery, and a permanent pacemaker was placed again 22-39 days after surgery. At 1-107 months of postoperative follow-up, no recurrence of infection was observed and the pacemakers were in good working condition. Perioperative management: All patients were treated preoperatively with antimicrobial agents according to blood culture results, and intravenous vancomycin was applied for those without bacteriological evidence. Those with severe infection and significant wasting could be given small amounts of plasma infusion several times before surgery. Intraoperative culture of the superfluous organisms was retained and the type of antibiotics was adjusted according to the culture results. Postoperative temporary epicardial pacing was applied, and the permanent pacemaker was placed again after the infection was completely controlled, the body temperature and blood picture were normal, and the blood culture was negative (see Table 1 and Table 2 for details). Discussion 1. Pathogenic characteristics of CDIE. Staphylococcus is the most common pathogenic bacteria of CDIE. In our group of 8 patients, 6 had positive bacterial cultures, including 5 cases of staphylococci (2 cases of Staphylococcus aureus, 1 case of Staphylococcus epidermidis, and 1 case of mixed infection with Staphylococcus wolframii and Staphylococcus haemolyticus). This is consistent with the literature [[5]]. According to this feature, patients with clinical diagnosis of CDIE should apply antibiotics according to the results of bacterial culture, and the treatment before the absence of bacteriological evidence should first choose antibiotics against cocci. 2, Analysis of the cause of infection. None of the cases in this group were first-time pacing device installers; all of them had a history of more than two pacing device operations, and the literature also reported that the incidence of infection was significantly higher in the second pacing device installation than in the first installation [[6]]. This may be due to the need to dispose of the previous local wound during the second operation. The previous surgical operation is mostly scar tissue with low local resistance and prone to infectious complications. This clinical phenomenon requires that we must strictly grasp the principle of asepsis when performing pacing device installation, especially when operating on more than two pacing devices. In this group of patients, three infections were first manifested as local symptoms, which failed to heal after debridement and developed into CDIE, and one patient had a postoperative local infection, which was not treated by out-of-hospital debridement more than 20 times. For various reasons, these debridements failed to completely remove the pacing leads and devices. The most thorough way to remove the pacing leads and devices in case of clinical pacing device infection is to wait until the infection is completely controlled before installing the pacing device. Incomplete “debridement” will only increase the difficulty and risk of healing. 3. Removal of pacing electrodes. The difficult part of pacing device removal is the removal of permanent pacing electrodes. Because of the presence of tricuspid valve and pacing electrode redundancy in pacemaker-associated infective endocarditis, the possibility of pulmonary embolism is a major concern when removing pacing electrodes via the vein. In the literature by Jon A. Grammes et al, the maximum flab present during transvenous electrode removal was 4 cm [[7]]. The presence or absence of flab is not a contraindication for transvenous electrode removal. In our group of eight cases of pacemaker-related infective endocarditis, the pacing electrodes were removed under open-chest extracorporeal circulation in seven cases of cardiac surgery, and in one case, the electrodes were removed via deep vein. Transvenous removal is a local anesthetic operation, which is less traumatic, quicker to recover, and easier for patients to accept. However, transvenous removal has many disadvantages, because the pacing electrodes placed for many years are heavily adhered to the heart tissue, there is a risk of heart perforation during removal, which requires experienced operators and should be performed in cardiac surgery with adequate preparation for open-heart surgery. In addition, the transvenous approach does not allow simultaneous treatment of the tricuspid valve, which is a disadvantage if the patient has tricuspid valve dysfunction. Third, for pacemaker-dependent patients, the problem of how to pace the heart after intravenous removal of the pacing electrodes is faced, because even if new electrodes are placed at the infected site, it will be more difficult to control the infection, while the epicardial temporary pacing method can be chosen after open-heart surgery to remove the intracardiac electrodes, and none of our 7 patients with open-heart surgery to remove the electrodes recurred. Fourthly, due to the presence of redundancy on the electrodes in CDIE patients, pulmonary embolism complications may occur during transvenous removal. Since only one case in our data group chose to remove electrodes via deep vein, no pulmonary embolism occurred, but a large sample of clinical cases is needed for observation. Removal of pacing electrodes under extracorporeal circulation in open-chest surgery is a major operation under general anesthesia, and there are certain surgical risks, which are its disadvantages. However, the removal of electrodes by open-heart surgery can remove infected lesions, especially when multiple pacing electrodes are present in the heart, and can provide treatment such as repair of the tricuspid valve according to the condition of the tricuspid valve, and can also deal with cardiac co-morbidities, which is incomparable to the removal of electrodes via the vein. We believe that the removal of infected electrodes and pacing devices for CDIE should be done on an individual basis. Open-heart surgery should be chosen for the removal of pacing electrodes and devices in the following cases: 1) where the infection-related electrodes cannot be removed via the implantation site or where removal has failed; 2) where the patient has other cardiac conditions that require simultaneous surgery; 3) where the bulky mass is too large to avoid pulmonary embolism; and 4) where surgical intervention is required due to valve dysfunction caused by infective endocarditis. For patients who are not pacemaker-dependent and have an ICD installed, especially those who have recently installed a pacing device can choose to remove the pacing electrodes and pacing device via the deep vein. 4. Timing of pacemaker reimplantation: infective endocarditis requires the application of regular application of antibiotics for 4-6 weeks, while pacemaker-related infective endocarditis requires complete clearance of the infection before reimplantation of a new pacemaker [8]. Therefore, to prevent recurrence of the infection, reimplantation of the pacemaker should be delayed as much as possible. In our data, the pacemaker implantation time ranged from 22-37 days. Since the epicardial pacing lead was placed for temporary epicardial pacing after removal of intracardiac electrodes under extracorporeal circulation in our data set, the time window for reimplantation of the pacemaker can be extended as much as possible with good epicardial pacing function. In our experience, a well placed epicardial pacing lead can work continuously for about a month before reimplantation of a permanent pacing device when we observe a significant increase in the pacing threshold due to oxidation of the epicardial pacing electrodes. However, the latest guidelines state that a new pacing device can be placed 3-14 days after infection-related pacemaker device removal with a negative blood culture [[9]]. Therefore, further clinical observations are needed regarding the optimal time for pacemaker reimplantation.