Stepwise transvenous lead extraction due to pacemaker pocket infection following lactational mastitis complicated with breast abscess.

BACKGROUND: Lactational mastitis is a common painful and debilitating inflammation of breast tissue, generally treated conservatively or with pus puncture in case of breast abscess. However, treating mastitis in patients with implantable surgical material located in the affected breast region can be extremely challenging. We present an unusual case of lactational mastitis complicated by pacemaker pocket infection in a breastfeeding mother. CASE PRESENTATION: A 35-year-old pacemaker-dependent female developed lactational mastitis seven weeks postpartum. Initially, the condition was treated conservatively with analgesics and antibiotics. After abscess formation, pus was aspirated using fine-needle aspiration technique. Four weeks after mastitis resolution, pacemaker pocket infection developed. According to current cardiovascular implantable electronic device infection treatment guidelines a complete surgical extraction of the entire electronic system, followed by targeted antibiotic treatment and reimplantation of a new device after infection resolution, was recommended. However, after thorough discussion with the young woman and her family and after detailed review of surgery-related risks, she declined a potentially high-risk surgical procedure. Thus, only the pulse generator was explanted; pacing leads positioned in the sub-pectoral pocket; new pacemaker implanted on the contralateral side and broad-spectrum antibiotic therapy continued for six weeks. After breastfeeding cessation, and with chronic fistula development at the primary pacemaker implantation site, the possibility of delayed surgical intervention including complete extraction of retained pacemaker leads was again thoroughly discussed with her. After thoughtful consideration the woman consented to the proposed treatment strategy. A surgical procedure including transvenous lead extraction through the primary implantation venous entry site, using hand-powered bidirectional rotational sheaths, was successfully performed, removing all retained leads through the left subclavian venous entry site, and leaving the fully functional and clinically uninfected pacemaker on the contralateral site intact. CONCLUSION: Although patients' decisions for delayed extraction in a case of cardiovascular implantable electronic device infection should be discouraged by attending physicians and members of interdisciplinary teams, our case shows that a stepwise treatment strategy may be successful as a bailout clinical scenario in patients with specific requests, demands and / or clinical needs.

Permanent Pacemaker Implantation and Long-Term Outcomes of Patients Undergoing Concomitant Mitral and Tricuspid Valve Surgery.

BACKGROUND: Tricuspid valve annuloplasty (TA) during mitral valve repair (MVr) is associated with increased risk of permanent pacemaker (PPM) implantation, but the magnitude of risk and long-term clinical consequences have not been firmly established. OBJECTIVES: This study assesses the incidence rates of PPM implantation after isolated MVr and following MVr with TA as well as the associated long-term clinical consequences of PPM implantation. METHODS: State-mandated hospital discharge databases of New York and California were queried for patients undergoing MVr (isolated or with concomitant TA) between 2004 and 2019. Patients were stratified by whether or not they received a PPM within 90 days of index surgery. After weighting by propensity score, survival, heart failure hospitalizations (HFHs), endocarditis, stroke, and reoperation were compared between patients with or without PPM. RESULTS: A total of 32,736 patients underwent isolated MVr (n = 28,003) or MVr + TA (n = 4,733). Annual MVr + TA volumes increased throughout the study period (P < 0.001, trend), and PPM rates decreased (P < 0.001, trend). The incidence of PPM implantation <90 days after surgery was 7.7% for MVr and 14.0% for MVr + TA. In 90-day conditional landmark-weighted analyses, PPMs were associated with reduced long-term survival among MVr (HR: 1.96; 95% CI: 1.75-2.19; P < 0.001) and MVr + TA recipients (HR: 1.65; 95% CI: 1.28-2.14; P < 0.001). In both surgical groups, PPMs were also associated with an increased risk of HFH (HR: 1.56; 95% CI: 1.27-1.90; P < 0.001) and endocarditis (HR: 1.95; 95% CI: 1.52-2.51; P < 0.001), but not with stroke or reoperation. CONCLUSIONS: Compared to isolated MVr, adding TA to MVr was associated with a higher risk of 90-day PPM implantation. In both surgical groups, PPM implantation was associated with an increase in mortality, HFH, and endocarditis.

Cardiac implantable electronic device-induced tricuspid regurgitation: Implications and management.

Tricuspid regurgitation (TR) secondary to cardiac implantable electronic devices (CIEDs) has been well documented and is associated with worse cardiovascular outcomes. A variety of mechanisms have been proposed including lead-induced mechanical disruption of the tricuspid valvular or subvalvular apparatus and pacing-induced electrical dyssynchrony. Patient characteristics such as age, sex, baseline atrial fibrillation, and pre-existing TR have not been consistent predictors of CIED-induced TR. While two-dimensional echocardiography is helpful in assessing the severity of TR, three-dimensional echocardiography has significantly improved accuracy in identifying the etiology of TR and whether lead position contributes to TR. Three-dimensional echocardiography may therefore play a future role in optimizing lead positioning during implant to reduce the risk of CIED-induced TR. Optimal lead management strategies in addition to percutaneous interventions and surgery in alleviating TR are very important.

Postoperative Atrioventricular Block in Pediatric Patients: Impact of Congenital Cardiac Malformations and Medications.

Postoperative atrioventricular block may occur after pediatric cardiac surgery. A small proportion of those who develop atrioventricular block will require pacemaker placement. The primary aim of this study was to determine factors associated with postoperative atrioventricular block. Secondary aims included determining factors associated with pacemaker placement in those with atrioventricular block. Data from the PHIS data were utilized to identify patients under 18 years of age who underwent cardiac surgery. Those who did and did not develop atrioventricular block. Univariable analyses and regression analyses were conducted to determine factors associated with postoperative atrioventricular block. Similar analyses were conducted to determine factors associated with pacemaker placement in those with atrioventricular block. A total of 43,716 admissions were identified. Of these, 2093 (5%) developed atrioventricular block and 480 (1% of total admissions) underwent pacemaker placement. Approximately 70% of those with atrioventricular block received steroids but this was not associated with a decrease in pacemaker placement. Risk factors (congenital malformations of the heart, comorbidities, medications) associated with increased risk of atrioventricular block and pacemaker placement were identified. Postoperative atrioventricular block occurred in 5% of pediatric admissions for cardiac surgery. Of these admissions with postoperative atrioventricular block, 23% required pacemaker placement. Isoproterenol and steroids were not associated with a reduction in the likelihood of pacemaker placement.

Cardiac implantable electronic devices in female patients: Esthetic, breast implant, and anatomic considerations.

INTRODUCTION: The implantation of a cardiac implantable electronic device (CIED) can have esthetic and psychological consequences on patients. We explore a heart team model for care coordination and discuss esthetic approaches for improved cosmetic outcomes in patients undergoing (CIED)-related procedures or de novo implantation. METHODS: Patients undergoing CIED surgery for approved indications between June 2015 and June 2022 were identified. Patients were included when surgical care was provided by a collaborative relationship between the primary electrophysiologist and the plastic surgeon. Patient demographics, details of the surgical procedure, information on breast implants, complications, and outcomes related to cosmesis were recorded. RESULTS: Twenty-two female patients were included in this study. The mean age was 50.2 ± 18.2 years. The mean follow-up duration was 2.2 ± 5.5 months. The top two indications for the procedure included CIED generator change (n = 9, 41%) and implantable cardioverter-defibrillator (ICD) implantation (n = 7, 32%). The most common reasons for involving plastic surgery in the procedure included surgery near breast implants (n = 10, 45%) and device displacement or discomfort (n = 8, 36%). CIED pocket position was prepectoral in 10 cases (45%), subpectoral in 11 patients (50%), and intramuscular in one patient (4.5%). The majority of the patients (20, 91%) had cosmetically acceptable results postprocedure. One patient (4.5%) had breast asymmetry on the CIED side, and another continued to have skin erosion over the CIED and leads. CONCLUSION: A heart team approach incorporating the expertize of cardiac electrophysiology and plastic surgery is essential for providing optimal care for patients with breast implants and patients requesting esthetic appeal.

Effect of age on in-hospital outcomes of transvenous lead extraction for infected cardiac implantable electronic device.

BACKGROUND: The real-world data on the safety profile of transvenous lead extraction (TLE) for infected cardiac implantable electronic devices (CIED) among elderly patients is not well-established. This study aimed to evaluate the hospital outcomes between patients of different age groups who underwent TLE for infected CIED. METHOD: Using the Nationwide Readmissions Database, our study included patients aged ≥18 years who underwent TLE for infected CIED between 2017 and 2020. We divided the patients into four groups: Group A. Young (<50 years), Group B. Young intermediate (50-69 years old), Group C. Older intermediate (70-79 years old), and Group D. Octogenarian (≥80 years old). We then analyzed the in-hospital outcome and 30-day readmission between these age groups. RESULTS: A total of 10,928 patients who were admitted for TLE of infected CIED were included in this study: 982 (9.0%) patients in group A, 4,234 (38.7%) patients in group B, 3,204 (29.3%) patients in group C and 2,508 (23.0%) of patients in group D. Our study demonstrated that the risk of early mortality increased with older age (Group B vs. Group A: OR: 1.92, 95% CI: 1.19-3.09, p < .01; Group C vs. Group A: OR: 2.47, 95% CI: 1.51-4.04, p < .01; Group D vs. Group A: OR: 2.82, 95% CI: 1.69-4.72, p < .01). The risk of non-home discharge also increased in elderly groups (Group B vs. Group A: OR: 1.89; 95% CI: 1.52-2.36; p < .01; Group C vs. Group A: OR: 2.82; 95% CI 2.24-3.56; p < .01; Group D vs. Group A: OR: 4.16; 95% CI: 3.28-5.28; p < .01). There was no significant difference in hospitalization length and 30-day readmission between different age groups. Apart from a higher rate of open heart surgery in group A, the procedural complications were comparable between these age groups. CONCLUSION: Elderly patients had worse in-hospital outcomes in early mortality and non-home discharge following the TLE for infected CIED. There was no significant difference between elderly and non-elderly groups in prolonged hospital stay and 30-day readmission. Elderly patients did not have a higher risk of procedural complications.

Temporal relationship between haemodynamic changes and activation of closed-loop stimulation during a tilt-induced vasovagal syncope.

AIMS: A dual-chamber pacemaker with closed-loop stimulation (CLS) mode is effective in reducing syncopal recurrences in patients with asystolic vasovagal syncope (VVS). In this study, we explored the haemodynamic and temporal relationship of CLS during a tilt-induced vasovagal reflex. METHODS AND RESULTS: Twenty patients underwent a tilt test under video recording 3.9 years after CLS pacemaker implantation. Three patients were excluded from the analysis because of no VVS induced by the tilt test (n = 1) and protocol violation (n = 2). In 14 of the remaining 17 patients, CLS pacing emerged during the pre-syncopal phase of circulatory instability when the mean intrinsic heart rate (HR) was 88 ± 12 b.p.m. and systolic blood pressure (SBP) was 108 ± 19 mmHg. The CLS pacing rate thereafter rapidly increased to 105 ± 14 b.p.m. within a median of 0.1 min [inter-quartile range (IQR), 0.1-0.7 min] when the SBP was 99 ± 21 mmHg. At the time of maximum vasovagal effect (syncope or pre-syncope), SBP was 63 ± 17 mmHg and the CLS rate was 95 ± 13 b.p.m. The onset of CLS pacing was 1.7 min (IQR, 1.5-3.4) before syncope or lowest SBP. The total duration of CLS pacing was 5.0 min (IQR, 3.3-8.3). Closed-loop stimulation pacing was not observed in three patients who had a similar SBP decrease from 142 ± 22 mmHg at baseline to 69 ± 4 mmHg at the time of maximum vasovagal effect, but there was no significant increase in HR (59 ± 1 b.p.m.). CONCLUSION: The reproducibility of a vasovagal reflex was high. High-rate CLS pacing was observed early during the pre-syncopal phase in most patients and persisted, although attenuated, at the time of maximum vasovagal effect. REGISTRATION: ClinicalTrials.gov identifier: NCT06038708.

Staged therapeutic surgery for progressive pulmonary regurgitation and pacemaker induced cardiomyopathy after the tetralogy of fallot repair.

BACKGROUND: Recently, improvements in the repair of tetralogy of Fallot have increased the need for reoperation in adulthood, and it's not rare that these reoperation candidates suffer from biventricular failure. However, there are no firm treatment guidelines, and each country, and even each facility, treats each case individually. CASE PRESENTATION: We report the successful staged treatment of pulmonary regurgitation and pacemaker-induced cardiomyopathy with biventricular failure in adulthood in a case of complete atrioventricular block after tetralogy of Fallot repair in childhood. We planned a staged therapeutic strategy with preoperative left ventricular volume reduction with medication, following surgical pulmonary valve replacement concomitant epicardial lead implantation on the lateral basal wall, placed just beneath the generator pocket through 3rd intercostal space. in addition to postoperative intervention with a defibrillator to adjust cardiac resynchronization therapy, resulted in improvement of symptoms. CONCLUSION: In a patient with biventricular failure after TOF repair, a staged treatment strategy involving medication, PVR, and CRT with a combination of epicardial and intravenous leads could be a useful treatment worth trying before heart transplantation.

Right ventricular lead perforation with iatrogenic injury to an intercostal artery causing haemothorax after pacemaker implant.

A woman in her 80s experienced a life-threatening complication of pacemaker implant consisting of subacute right ventricular lead perforation causing iatrogenic injury to an intercostal artery, resulting in a large haemothorax. A CT scan confirmed active bleeding from the fourth intercostal artery. The patient underwent cardiothoracic surgery via a median sternotomy approach, during which the source of the bleeding was sealed, a new epicardial lead was positioned, and the original lead was extracted. This case emphasises the potentially severe consequences of pacemaker lead perforation and secondary injury to adjacent structures. It underscores the importance of early recognition and timely intervention, preferably in a tertiary specialist unit equipped for cardiothoracic surgery and confirms the value of pacemaker interrogation and CT scans for diagnosis.

Perioperative Considerations for Modern Leadless Pacemakers.

Since their initial approval by the Food and Drug Administration in 2016, leadless pacemakers have become increasingly prevalent. This growth has been driven by an improved adverse effect profile when compared to traditional pacemakers, including lower rates of infection, as well as eliminated risk of pocket hematoma and lead complications. More recently, technology enabling leadless synchronized atrioventricular pacing in patients with atrioventricular block has vastly expanded the indications for these devices. Anesthesiologists will increasingly be relied upon to safely care for patients with leadless pacemakers undergoing non-electrophysiology procedures and surgery. This article provides an overview of the technology, evidence base, current indications, and unique perioperative considerations for leadless pacemakers.

Treatment of cardiac implantable electronic device endocarditis in pacemaker-dependent patients utilizing a percutaneous aspiration system.

With the increasing use of cardiac implantable electronic devices, the number of patients with cardiac implantable electronic device-related endocarditis is also rising. The treatment of this type of endocarditis is a challenging clinical task, in particular if device removal is required in patients who are pacemaker dependent. This video tutorial describes a treatment strategy for cardiac implantable electronic device-related endocarditis involving the tricuspid valve in pacemaker-dependent patients. The proposed treatment strategy consists of implanting an epicardial pacemaker via a minimally invasive subxiphoid approach, percutaneous aspiration of tricuspid valve vegetations and complete transvenous explantation of the infected cardiac implantable electronic device system using advanced lead extraction tools.

The effect of body mass index on complications in cardiac implantable electronic device surgery.

BACKGROUND: Cardiac implantable electronic device (CIED) procedures are prone to complications. In our study, we investigated the effect of body mass index (BMI) on CIED-related complications. METHODS: 1676 patients who had undergone CIED surgery (de novo implantation, system upgrade, generator change, pocket revision or lead replacement) at two heart centers in Turkey and met the study criteria were included in our study. For analysis of primary and secondary endpoints, patients were classified as non-obese (BMI < 25 kg/m2 ), overweight (25 ≤ BMI < 30 kg/m2 ), and obese (BMI ≥ 30 kg/m2 ). The primary endpoint was accepted as cumulative events, including the composite of clinically significant hematoma (CSH), pericardial effusion or tamponade, pneumothorax, and infection related to the device system. Secondary outcomes included each component of cumulative events. RESULTS: The rate of cumulative events, defined as primary outcome, was higher in the obese patient group, and we found a significant difference between the groups (3.0%, 4.3%, 8.9%, p = .001). CSH and pneumothorax rates were significantly higher in the obese patient group (0.3%, 0.9%, 1.9%, p = .04; 1.0%, 1.4%, 3.3%, p = .04, respectively). According to our multivariate model analysis; gender (OR:1.882, 95%CI:1.156-3.064, p = .01), hypertension (OR:4.768, 95%CI:2.470-9.204, p < .001), BMI (OR:1.069, 95%CI:1.012-1.129, p = .01) were independent predictors of cumulative events rates. CONCLUSIONS: Periprocedural complications associated with CIED (especially hematoma and pneumothorax) are more common in the group with high BMI.

[Surgical Removal of a Transvenous Pacemaker Lead with the Right Atrial Perforation:Report of a Case].

Cardiac perforation by a transvenous pacemaker lead is an uncommon, but serious complication. Management strategies in pacemaker lead cardiac perforation depend on the symptoms, the presence of pericardial effusion, hemodynamic status, and injured neighboring organs. A 70-year-old man was admitted due to suspicious right atrial perforation with pneumothorax secondary to a transvenous pacemaker lead. Right atrial perforation was confirmed on computed tomography (CT). A large laryngopharyngeal hemangioma compressing the trachea was also observed. Although he was hemodynamically stable, we chose a surgical removal of a transvenous pacemaker lead considering his large laryngopharyngeal hemangioma. A tracheotomy followed by lower hemisternotomy were performed. A perforated pacemaker lead was observed on the right atrium. The lead was pulled out, and a hole in the right atrium was fixed. His postoperative course was uneventful.

[Surgical Treatment of the Perforation of the Right Ventricle and Diaphragm by a Permanent Pacing Lead:Report of a Case].

An 97-year-old woman was diagnosed with complete atrioventricular block and underwent pacemaker implantation( PMI). Three days after the PMI, computed tomography revealed cardiac perforation and migration of the lead to the abdominal cavity. Surgical procedure through median sternotomy was performed, and the penetrated lead was removed. The holes of the right ventricle and diaphragm were repaired. Abdominal organ was not injured. She was discharged 14 days after the surgical procedure.

Hospitalization for permanent pacemaker implantation in the context of isolated sinus node dysfunction is associated with increased mortality compared with an outpatient strategy.

BACKGROUND: Permanent pacemaker (PPM) implantation is a well-established treatment for symptomatic sinus node dysfunction (SND). The optimal timing of this intervention is unclear, with atrioventricular blocks often prioritized in resource stressed waiting lists due to mortality concerns. METHODS: Mortality data was compared between patients receiving elective outpatient (OP) PPM implantation, and those presenting to hospital for urgent inpatient (IP) management for symptomatic SND. Survival analysis was conducted using Kaplan-Meier plots and compared using the log-rank test. Univariable and multivariable Cox regression, as well as propensity score matching analyses were performed to assess the prognostic effect on 30-day and 1-year all-cause mortality of inpatient implant. RESULTS: Of the 1269 patients identified with isolated SND, 740 (58%) had PPMs implanted on an OP and 529 (42%) on an IP basis. Mortality was significantly worse in patients where management was driven by hospital admission on an urgent basis (Log-Rank χ2 = 21.6, p < 0.001) and remained an independent predictor of 1-year all-cause mortality (HR 3.40, 95% CI 1.97-5.86, p < 0.001) on multivariable analysis. CONCLUSIONS: SND is predominantly a disease associated with ageing and comorbid populations, where avoidance of deconditioning, hospitalization acquired infections, and polypharmacy is advantageous. Admission avoidance is therefore the preferable strategy.

Research and Prediction of Factors Related to High Degree Atrioventricular Block after TAVI Surgery Based on Logistic Regression Model.

OBJECTIVE: Based on the logistic regression model, analyze the risk factors for high degree atrioventricular block after transcatheter aortic valve replacement (TAVI) surgery and further analyze its predictive value. METHODS: 402 patients who underwent TAVI surgery at Henan Thoracic Hospital for "aortic stenosis" between January 2020 and January 2023 were selected as the study subjects. The study subjects were divided into A group (N = 89) and B group (N = 313) based on whether high degree atrioventricular block occurred after surgery. The age, biochemistry and other general data of patients were systematically collected through inpatient cases, and the preoperative Right bundle branch block, I degree atrioventricular block, QRS duration, and indoor block were collected through our hospital's electrocardiogram (ECG) system, Calcification integral of Aortic valve was calculated by computed tomography (CT) results. Logistic regression analysis was performed on the clinical data, and the predictive value of related factors was further analyzed through the Receiver operating characteristic. RESULTS: The preoperative QRS wave duration in the A group (165.06 ± 61.25) was significantly higher than that in the B group (108.30 ± 16.30), and the difference was statistically significant (p < 0.05). Compared with the B group, the incidence of Right bundle branch block in the A group was significantly higher before operation. The calcification score of Aortic valve in the A group (97.58 ± 61.25) was significantly higher than that in the B group (43.59 ± 7.56), with a statistically significant difference (p < 0.05). Further multivariate logistic regression analysis showed that the duration of QRS wave before operation and Aortic valve calcification score were independent risk factors for high atrioventricular block after TAVI (p < 0.05). Through Receiver operating characteristic analysis, it was found that preoperative QRS wave duration and Aortic valve calcification score had a high predictive value for the occurrence of high atrioventricular block after TAVI. The optimal cutoff value of QRS wave duration for predicting high atrioventricular block was 152, area under curve (AUC): 0.780 (95% CI: 0.718-0.841, p < 0.001). The optimal cutoff value for predicting high degree atrioventricular block with aortic calcification score is 61.5, AUC: 0.997 (95% CI: 0.992-1.000, p < 0.001). CONCLUSIONS: Preoperative QRS wave duration and Aortic valve calcification score are independent risk factors for high degree atrioventricular block after TAVI, and they have high predictive value. In clinical work, risk factors should be found early and responded in time.

Cost of Pacing in Pediatric Patients With Postoperative Heart Block After Congenital Heart Surgery.

Importance: Surgical correction of congenital heart defects (CHDs) has improved the lifespan and quality of life of pediatric patients. The number of congenital heart surgeries (CHSs) in children has grown continuously since the 1960s. This growth has been accompanied by a rise in the incidence of postoperative heart block requiring permanent pacemaker (PPM) implantation. Objective: To assess the trends in permanent pacing after CHS and estimate the economic burden to patients and their families after PPM implantation. Design, Setting, and Participants: In this economic evaluation study, procedure- and diagnosis-specific codes within a single-institution database were used to identify patients with postoperative heart block after CHS between January 1, 1960, and December 31, 2018. Patients younger than 4 years with postoperative PPM implantation were selected, and up to 20-year follow-up data were used for cost analysis based on mean hospital event charges and length of stay (LOS) data. Data were analyzed from January 1, 2020, to November 30, 2022. Exposure: Implantation of PPM after CHS in pediatric patients. Main Outcomes and Measures: Annual trends in CHS and postoperative PPM implantations were assessed. Direct and indirect costs associated with managing conduction health for the 20 years after PPM implantation were estimated using Markov model simulation and patient follow-up data. Results: Of the 28 225 patients who underwent CHS, 968 (437 female [45.1%] and 531 male [54.9%]; 468 patients aged <4 years) received a PPM due to postoperative heart block. The rate of CHS and postoperative PPM implantations increased by 2.2% and 7.2% per year between 1960 and 2018, respectively. In pediatric patients younger than 4 years with PPM implantation, the mean (SD) 20-year estimated direct and indirect costs from Markov model simulations were $180 664 ($32 662) and $15 939 ($1916), respectively. Using follow-up data of selected patients with clinical courses involving 1 or more complication events, the mean (SD) direct and indirect costs were $472 774 ($212 095) and $36 429 ($16 706), respectively. Conclusions and Relevance: In this economic evaluation study, the cost of PPM implantation in pediatric patients was found to accumulate over the lifespan. This cost may represent not only a substantial financial burden but also a health care burden to patient families. Reducing the incidence of PPM implantation should be a focused goal of CHS.

[Lead extraction in cardiac implantable electronic devices]. / Sondenextraktionen bei implantierbaren kardialen Devices.

Lead extraction due to infection or lead dysfunction has become more important in recent years. Patients with high risk of severe and life-threatening complications should only undergo surgery in experienced centers where appropriate personnel and equipment are available. In this review, different techniques and methods to safely and successfully perform transvenous lead extraction are summarized.

Monocyte/High-Density Lipoprotein Ratio Is Associated with Atrial High-Rate Episodes within One Year Detected by Cardiac Implantable Electronic Devices.

OBJECTIVE: To investigate the risk factors for predicting atrial high-rate episodes (AHREs) detected by cardiac implantable electronic devices (CIEDs). METHODS: A total of 140 patients with CIED in our hospital from June 2013 to June 2018 were included and were followed up to observe whether they had AHREs. AHRE are defined as atrial rate ≥ 175 times/minute, lasting > 5 minutes, and reviewed by an experienced electrophysiologist with unclear clinical diagnosis. The patients fasted for 12 hours after implantation, and blood samples were collected for biochemical, lipid, and whole blood count detection. Follow-up was regular after discharge to record follow-up data of each patient and conduct statistical analysis. RESULTS: One hundred and forty patients were implanted with dual-chamber pacemakers, their median age was 70 years old, 44.29% were male, 27 patients had AHRE within one year, and AHRE incidence rate was 19.29%. The microcytic to hypochromic (M/H) ratio was calculated for all AHRE patients and compared with the patients without AHRE; the M/H value of AHRE patients was significantly higher. Throughout the entire follow-up period, a total of 44 patients developed AHRE; when adjusted by multivariate analysis, only M/H ratio ≥ 4.5 vs. < 4.5 had statistical significance, and the adjusted hazard ratio value was 4.313 (1.675-11.105). CONCLUSION: As an indicator, M/H ratio may play an important role in the occurrence and development of atrial fibrillation and can be used as a predictor of AHRE in patients with CIED.